THE LASER USER ISSUE 99 ISSUE 99 WINTER 2021 THE WINTER 2021 LASER IN THIS ISSUE: USER Hollow core fibres Interference patterning
Anti-bacterial surfaces
Medical wire stripping PROGRAMME INSIDE Automotive laser welding
GROUND-BREAKING ONLINE SYMPOSIUM: ILAS 2021 - NETWORKING WITHOUT BORDERS 1 ISSUE 99 WINTER 2021 THE LASER USER
THE LASER USER
Editor: Dave MacLellan Sub-Editor: Catherine Rose
ISSN 1755-5140
© 2021 – Association of Industrial Laser Users
The Laser User is the house magazine of the Association of Industrial Laser Users. Its primary aim is to disseminate technical information and to present the views of its members. The views and opinions expressed in this magazine belong to the authors and do not necessarily reflect those of AILU.
The Editor reserves the right to edit any submissions for space and other considerations. Cover image: A high power diode laser in the blue wavelength (450 nm) performs pore-free cladding Authors retain the right to extract, in part or in whole, their material (Laser Metal Deposition) with copper powder onto for future use. The Laser User is published quarterly in February, May, a copper workpiece. August and November by AILU for its members and is available in print or online. Courtesy of Laserline GmbH, Germany
Editorial Board for this issue: Chris Allen TWI Ric Allott STFC Jon Blackburn TWI Jan Brajer Hilase Centre Emmanuel Brousseau Cardiff University Stefan Dimov University of Birmingham David Earl Laser Lines Duncan Hand Heriot-Watt University Mark Millar Essex Laser AILU STEERING COMMITTEE Wojciech Suder Cranfield University 2020-21 David Waugh Coventry University President: Jon Blackburn (TWI) Vice President: Adam Clare (University of Nottingham) Exec. Director: Dave MacLellan (Anode Marketing) ADVERTISING ENQUIRIES Elected until 2023 Paola De Bono (TWI) +44 (0) 1235 539595 Tom Chaffer (TRUMPF) [email protected] Advertising rates at: Elected until 2022 http://bit.ly/AILU2020Media Richard Carter (Heriot-Watt University) Hollie Denney (II-VI) Matthew Wasley (Knowledge Transfer Network)
Elected until 2021 Derrick Jepson (Aerotech) Arina Mohammed (University of Hull) Mark Thompson (IPG Photonics)
WELCOME TO NEW Co-opted AILU MEMBERS Jonathan Lawrence (Coventry University) Mark Millar (Essex Laser) Association of Industrial Laser Users Tony Jones (Cyan Tec Systems) Oxford House Mike Poulter (SPI Lasers) 100 Ock Street Central Laser Services Ltd Cliff Jolliffe (PI) Abingdon Steve Evans Oxfordshire steve@centrallaserservices. Past presidents and founder members are also able to OX14 5DH co.uk attend committee meetings. Anyone wishing to join the AILU Steering Committee please contact the Executive Tel: +44 (0) 1235 539595 SS Laser Solutions Director. E-mail: [email protected] Sinan Bilgin Web: www.ailu.org.uk [email protected]
2 THE LASER USER ISSUE 99 WINTER 2021 CONTENTS HIGHLIGHTS...
Hollow core Interference Anti-bacterial fibres 16 patterning 18 surfaces 20
Medical wire Automotive laser stripping 22 welding 24 29 ASSOCIATION NEWS MAIN FEATURES CONTENT BY SUBJECT First Word 4 Hollow core fibres for high Business President’s Message 4 power delivery in 1 µm region Members' News 5-8 Ric's Ramblings 4 Hesham Sakr et al. 16 Case Studies 9
How lasers can help reduce BUSINESS NEWS Interference patterning of food waste metallic substrates Business 5 Short feature 11 R&D 7 Petr Hauschwitz 18
Case Studies AILU Interview 12 9 Surface structures mitigate Product News 32-33 EARLY CAREER bacterial adhesion Anvesh Gaddam et al. 20 RESEARCHERS 11 Job Shop News 14 Down to the wire – laser Chair’s Report 15 SHORT FEATURES ablation of medical micro wires How lasers can help reduce Olivia Gillen & Michael Hollow core fibres Main Feature 16 food waste 11 O’Donnell 22 Excimer lasers & Interference patterning Laser Welding: high volume Main Feature superconducting tapes 28 18 manufacturing for e-mobility SMEs: first steps into AM 33 Anti-bacterial surfaces Pasquale Franciosa et al. 24 Main Feature 20 EDITORIAL Medical wire stripping
Main Feature 22 Interview: Cliff Jolliffe, Physik Observations 26
Instrumente (PI) 12 Automotive laser welding Main Feature Job Shop Corner 14 24 Chair's Message 15 Excimer lasers & A Funny Thing... 35 superconducting tapes Short Feature 28 PRODUCT NEWS SMEs: first steps into AM Systems & Sources 32 Short Feature 33 Ancillaries 32 Events 29-31, 35, 36
EVENTS 28, 35, 36 3 ISSUE 99 WINTER 2021 THE LASER USER ASSOCIATION NEWS
FIRST WORD PRESIDENT'S MESSAGE ILAS, which will be held virtually on the 24th and 25th March. We’ve selected Here's hoping that 2021 sees you all well and Fellow laser enthusiasts, an online platform that will include that before the year is out we will meet in the everything you have come to expect real world and not just online. Until then, don’t I'll begin with a late but heartfelt from this first-class symposium; hesitate to pick up the phone, send an email wish for a Happy New Year to you all – we hope you and your families or WhatsApp me, as we are always happy to • Plenary presenters are managing to stay safe and well, catch up with members we haven’t seen for • Three parallel sessions of and have found ways to cope with the a while. presentations including keynote added pressures that daily life now speakers AILU has been going since 1995, but every brings. year sees something new and this year it is • A full exhibition – with online our first ever full ILAS online. We are excited The Christmas period brought some interactivity – meet exhibitors 1-to-1 about the prospect of networking and welcome news to UK, with the • Live discussion panels on key topics MHRA approval of the AstraZeneca gathering the extensive ILAS community in • Excellent networking opportunities – vaccine, as well as the long-awaited one place over 2 days, even if it is online. If an online Meeting Hub to meet other agreement on a trade deal between you haven’t registered yet, it is still possible to delegates live or to suit your schedule the UK and the EU. Although there are join as an exhibitor, delegate or sponsor – this • Symposium Awards, including clearly some turbulent times ahead might be the first chance to meet so many entertainment – apply now if you have over the next few months, I think people in one event. I recommend you spend musical skills to display! plenty of time networking. If you don’t have these two announcements, and the the chance to see all the presentations you subsequent rate at which vaccinations The virtual format should also be would like, don’t worry as they will be available are progressing in the UK, point to a more inclusive, as it significantly for 12 months on video online to watch later. more stable (normal?) future in the reduces the costs to attend - in medium-term. I’m certainly looking registration and travel/accommodation See you soon at ILAS! forward to the time when I no longer fees, as well as the cost of evening have to spend my days finding a ‘refreshments’. Please think about balance between my duties for my who in your organisation could benefit Dave MacLellan long-standing employer (TWI) and from attending (I’ve not been to a [email protected] that of Head Teacher at the newly symposium for nearly 1 year!) and established Blackburn comprehensive visit the symposium website for more in East Anglia. I have been told that my details – ilas2021.co.uk OFSTED rating will not be favourable. Stay safe, 2020 was also not a straightforward Jon for AILU, with the postponement of ILAS and the inability to run physical workshops having quite an impact on Jon Blackburn the Association. We’re fortunate to have jon.blackburn@ a very hard-working and dedicated twi.co.uk team at AILU, who have adapted well to the challenges faced over the last year. A great example of this is the upcoming
RIC'S RAMBLINGS Then we consider being a member of the audience. If you have travelled, invested that time and battled on that train – you are much more receptive It’s a new dawn, a new day, a new [year] – and I’m feeling good… or so the to the talks and speakers. You want to learn and be entertained. But it is classic song (almost) goes. Well that was what we were supposed to be like much harder to focus when you are at home in your spare bedroom and post our little festive breaks- but hey ho, here we are again –all revved up there are other distractions around. Apart from the dog coming in or a small and no place to go (don’t worry I’ll drop the “link it to a song” theme now). child requiring a Penguin biscuit, we also get distracted by our emails or I thought I would pick up a bit on the subject of my ramblings last quarter a website or whatever. This means we are not getting as much out of the – the challenge of doing good, effective and productive business when we webinar as we should. Hence if you are coming to ILAS online in March, can’t be in the same room together. I don’t know about you but I am finding I recommend you plan ahead and get yourself in a comfortable position the new world of on-line conferences and webinars a bit of a mixed bag. – make sure you blend your time with networking and chatting to people – On one hand the delegate numbers have dramatically increased and in catching up with delegates you know and meeting new contacts. some cases appear to be through the roof, for a number of webinars that So, I have a request –let’s have a chat and meet I’ve attended. This is great, we are reaching far more people and engaging at ILAS – I would love to know what you think with a much broader audience. All this without having to fight for a seat on a and connect with many of you face-to-face train packed to the rafters and losing 2-3 hours of productive time travelling online. across the country. Ric Allott However, I find doing a presentation over a webinar lacks the visual feedback I enjoy as a presenter. When we do talks we take energy (or [email protected] otherwise) from the audience. We build our enthusiasm if points go down well, or pull back a bit if clearly the audience are not with you on that particular point. Online it is much harder to get the buzz from the audience. As time goes by, I am sure the technology will improve the experience. 4 THE LASER USER ISSUE 99 WINTER 2021
BUSINESS NEWS
COHERENT AND SPI LASERS IS NOW ATLAS COPCO ACQUIRES LUMENTUM TO COMBINE TRUMPF PURIFICATION SOLUTIONS Lumentum Holdings Inc. and Coherent, Inc. Atlas Copco has acquired the operating announced that they have entered into a business of Purification Solutions LLC and definitive agreement under which Lumentum will certain other affiliates, a leading compressed air acquire Coherent in a cash and stock transaction and gas solutions provider with a global sales valued at $5.7 billion. network. Purification Solutions LLC is a privately owned US-based company that focuses on the The combination unites Coherent's leading design, production and sales of air treatment photonics and lasers businesses, including in and on-site nitrogen generation equipment. the Microelectronics, Precision Manufacturing, Instrumentation, and Aerospace & Defence markets, with Lumentum's leading Telecom, Datacom, and 3D Sensing photonics TRUMPF has completed the renaming businesses, creating a diversified photonics and merger of its wholly-owned fibre laser technology company with significantly increased manufacturing subsidiary SPI Lasers, into scale and market reach. the TRUMPF group and under the TRUMPF brand. Effective from November 2020, the UK-based company SPI Lasers UK Ltd. will now operate under the name TRUMPF Laser UK Ltd.
As a result of this name change and merger, Contact: Arron Farghaly the former SPI Lasers organisation is now working even more closely with TRUMPF [email protected] Laser- und Systemtechnik GmbH, also a www.atlascopco.co.uk Contact: Jeff Nolan wholly-owned subsidiary of the TRUMPF [email protected] Group. The two companies are pooling www.coherent.com their competence and expertise in laser technology worldwide to create synergies and improve customer service for industrial applications in both disk laser and fibre laser TWI CELEBRATES 75 technology. LASER LINES IS UK YEARS OF INNOVATION Contact: Matt Wallis PARTNER FOR FLUENCE [email protected] Laser Lines has become the exclusive UK www.trumpf.com distributor for Fluence femtosecond fibre laser systems and diagnostics devices. Founded in 2016, Fluence sp. z o.o. is a Polish company that designs cutting-edge ultrafast lasers suitable for customers in micromachining, biophotonics and scientific research. FOUNDED IN 1971, II-VI CELEBRATES ITS 50th Founded by Dr. Carl Johnson, who introduced This year marks the 75th anniversary of optics for CO2 laser applications, II-VI Incorporated has added laser cutting heads, The Welding Institute and the purchase of one-micron optics, pump lasers, and many more Abington Hall near Cambridge by the British products to its expanding range. Welding Research Association in 1946. This remains the headquarters of TWI Ltd today.
TWI has gone on to expand across the UK, as well as gaining a presence around the world. The overseas centres have made TWI the largest provider of welding technology Contact: David Earl and inspection related training for both [email protected] individuals and companies; providing training www.laserlines.co.uk to over 20,000 people per year and further expanding work to promote and advance Contact: Hollie Denney [email protected] engineering across the world. www.ii-vi.com www.twi-global.com
5 ISSUE 99 WINTER 2021 THE LASER USER BUSINESS NEWS
NUBURU STRENGTHENS TRUMPF INVESTS IN LUXINAR HAS ACHIEVED BLUE LASER IP PORTFOLIO SMART PRODUCTION COVID-19 SECURE STATUS TRUMPF has opened a new smart factory Luxinar understands the importance of creating at its headquarters in Ditzingen and the new a safe environment for all of its employees and facility is already producing sheet metal parts has implemented over 60 policy changes at its for the company’s machine tools. The smart UK-based site, exceeding the recommendations factory also serves as a demonstration centre of both this survey and the UK government. – a place where SMEs and other businesses The result is that Luxinar has achieved COVID- can see for themselves how efficiently sheet 19 secure status, the government’s standard metal fabrication works. to ensure that companies are following best practice to manage the risk of coronavirus.
NUBURU announced that it has been awarded seven new patents across 3D printing and material processing. NUBURU’s blue lasers provide high speed and quality control for metal processing operations, such as welding and additive manufacturing in a variety of growing industries like e-mobility and automotive, where materials such as copper, stainless steel and Contact: Gerry Jones aluminum are increasingly critical. [email protected] Contact: Joanna Houldridge www.trumpf.com [email protected] Contact: Andrew Dodd www.luxinar.com [email protected] www.nuburu.net TRACEABILITY MARKING FROM MACSA ID COHERENT & II-VI JOIN IN AUTOMOTIVE WELDING XL PRECISION EXPANDS Coherent and II‐VI Inc have entered into a supply agreement creating a collaboration FACILITIES IN UK & USA to enable faster process development and streamlined production services for automotive laser welding applications. These include high-strength alloy welding for automotive body-in-white applications and mass production copper welding for Macsa id UK has been involved in the traceability electrification applications. marking of Rapid Antigen Testing for COVID- 19. With the D-Series laser a thermal mark is achieved in just 1.8 seconds.
Contact: Neil Greatorex [email protected] www.macsa.com XL Precision Technologies (XL-PT) has announced a major capital investment to expand facilities in the first quarter of 2021, BYSTRONIC & MSS after record performance in 2020. Over the past 3 years XL-PT has successfully NITROGEN IN PARTNERSHIP implemented a growth strategy which Contact: Roy Harris MSS Nitrogen Inc has entered into an exclusive resulted in 70% growth in revenue in both the [email protected] USA and UK. www.coherent.com agreement with Bystronic Inc to supply its nitrogen generators and gas mixers for the Contact: Darren Vine Contact: Hollie Denney American continent. [email protected] [email protected] www.II-VI.com Contact: Carlos Gonzalez-Lee www.xlprecisiontechnologies.com [email protected] www.msslasers.com
6 THE LASER USER ISSUE 99 WINTER 2021 R&D NEWS
NEW MEDICAL DEVICE MANUFACTURING CENTRE BASED AT HERIOT-WATT
Heriot-Watt University is leading a consortium of four Scottish universities (Heriot-Watt, Edinburgh, Glasgow, Robert Gordon) to develop the Medical Device Manufacturing Centre (MDMC), underpinned by an investment from the Advancing Manufacturing Challenge Fund. MDMC formally started on 1 April 2020 and despite some unavoidable delays due to COVID- 19 the hard-working staff have managed to both develop the Centre and to provide direct assistance to their clients, i.e. Scottish SMEs.
MDMC is designed to provide medical device developers and manufacturers with the advice, technical expertise and facilities essential for companies that are seeking to translate medical device concepts to commercial products. Its mission is to provide expert advice on Needham Laser Tech Benchtop laser marking/engraving machine and Sodi-Tech EDM Sinker Electrical manufacturing, engineering, regulatory issues Discharge Machine displayed by the MDMC team members Wojciech Gora and Paulina Morawska and funding, coupled with technically supported laser-based equipment (fibre laser marking/ The £3.7M Centre is jointly funded by the access to manufacturing facilities, all free of engraving workstation, fibre laser workstation, European Regional Development Fund (managed charge to Scottish SMEs. MDMC aims to assist laser cutting machine); a suite of analysis by Scottish Enterprise) the Edinburgh & South these Scottish companies in the translation of equipment, including microscopes, SEM, surface East Scotland City Region Deal, and the four medical device concepts through to small batch profiler, polishing and sectioning equipment; and universities. commercial prototypes. They have completed other manufacturing equipment including 3D work with 8 companies to date, and are currently printing machines, spray jetting of conductive directly engaging with a further 11 companies. inks, a 3D nanolithography machine, electro- Contact: Duncan Hand discharge machining (EDM) and injection [email protected] The MDMC facilities, housed in specially moulding. These facilities are currently being [email protected] refurbished laboratory space, include various procured and installed. www.mdmc.hw.ac.uk
THE MTC ANNOUNCES LASER-BASED FUNDING OPPORTUNITY FOR SMES
A funding opportunity for Small and Medium-sized Enterprises (SMEs) development of SME-friendly laser-based equipment and solutions. To has arisen through the MTC's partnership with other European institutions achieve this, it will set up a Europe-wide network to encourage SME on the EU Horizon 2020 PULSATE project. Laser-based advanced and participation in LBAAM innovation. It will therefore connect digital innovation additive manufacturing (LBAAM) technologies play an important role hubs to support a structure designed to tackle the issues currently in furthering digital production and offer important advantages to the hindering LBAAM technology adoption. The project’s work will help to companies that adopt them. However, barriers such as high investment increase the competitiveness of European SMEs. costs, complex technology, system integration, and awareness hinder their adoption by SMEs. https://pulsate-tte.fundingbox.com/ Contact: Tian Long See The EU-funded PULSATE project intends to mitigate these barriers to [email protected] boost the adoption of LBAAM technologies by SMEs and promote the www.the-mtc.org 7 ISSUE 99 WINTER 2021 THE LASER USER R&D NEWS
SCIENTISTS FROM HILASE AND STFC ACHIEVE A NEW WORLD RECORD FOR THE BIVOJ LASER
A team of scientists from the High Energy Slab Lasers group, led by Dr. Martin Divoký at the HiLASE Centre (Czech Republic), has significantly improved the world record of average power output from a high energy laser. This achievement was accomplished in cooperation with British partners from the Science and Technology Facilities Council’s (STFC) Central Laser Facility. The project is jointly funded by the H2020 “Widespread Teaming” programme and the Ministry of Education, Youth and Sports of the Czech Republic.
The BIVOJ laser system, a pulsed nanosecond diode-pumped solid-state laser developed at STFC’s Central Laser Facility, is a powerful kW laser and utilises a cryogenic cooling technology to achieve high average power output. At the end of 2016, the Czech-British team of scientists amplified laser pulses, with a pulse duration of 10 ns, a wavelength of 1030 nm to an energy of 105 J at a repetition rate of 10 Hz, thus setting a world record for the first kilowatt laser source in a given class of high-energy lasers. “Our British partners and representatives of the Czech and UK optical Now, four years later, the record from 2016 was surpassed by almost industries developed new coatings for optical elements with twice the 40%, reaching maximum output energy of 146.5 J in 10 ns pulses with a damage threshold compared to the original state of the art. This allowed us repetition rate of 10 Hz at a wavelength of 1030 nm. to reach the energy of 146.5 J, which is now very close to the physical and technical limits of the BIVOJ laser“. “Achieving 146.5 J at 10 Hz is a major milestone, which firmly establishes diode-pumped high power lasers at the forefront, significantly beyond flash- BIVOJ has already been used for a variety of applications in the aerospace, lamp pumped systems”, states Tomáš Mocek, Head of the HiLASE Centre. automotive and power engineering industries. In the future, the research “We have gained a great technological lead. It opens up the way to new and development will focus on improving the quality of the beam applications for materials processing, surface treatment and fundamental wavefront using adaptive optics and on compensating for the undesirable research into the interaction of high-power laser radiation with matter.” phenomenon of depolarisation, which occurs at these high powers in amplifier disks. The energy increase was achieved by pushing the limits of the current laser-induced damage threshold of the optical elements used in the laser. Contact: Tomáš Mocek “The laser-induced damage threshold of the optical elements limited the [email protected] output energy of the BIVOJ laser to around 100 J,” explains Martin Divoký. www.hilase.cz
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8 AH0219A-LPM-LTD-Optical Alignment-190x125.indd 1 3/16/2020 3:35:33 PM THE LASER USER ISSUE 99 WINTER 2021 CASE STUDIES
TRUMPF LASER CUTTER SUPPORTS CAR PANEL MANUFACTURE
QFS Technologies, a specialist supplier of of parts,” explains Managing Director Neil body-in-white (BIW) parts to the automotive Holloway. “Maybe the pandemic situation industry, has invested in a new TRUMPF where major production suppliers of panels TruLaser Cell 5030 five-axis (3D) laser cutter. being shut down during lockdown has Although the company has an older TRUMPF contributed to production dies being delayed, five-axis machine that has given many years but of course the OEM’s still need to meet of reliable service, QFS knew that investing their build schedules to sell vehicles. We’ve in the higher performance and richer feature found ourselves in a position to provide the set of the TruLaser Cell 5030 would provide necessary support.” a number of competitive advantages, When Mr Holloway recently put forward a particularly in relation to new project work for business case for a new project with a major a major customer. automotive customer, he realised that a new QFS develops and manufactures prototypes five-axis laser cutter would be required. The from single panels to complete assemblies for TRUMPF TruLaser Cell 5030 is the perfect BIW, concept and show vehicles. Customers entry-level solution for flexible 2D and 3D often continue to use the company’s laser cutting. With its low machine-hour unique blend of skills right through the initial rate, the TruLaser Cell 5030 is ideally suited prototype and manufacturing process, into to small and medium batch sizes, and for mass production. applications where components are frequently changed. “As we supply panels in batch quantities “getting there”, with the new laser already of 25-150 through various prototype build Installed in August 2020, the machine’s heavily utilised. phases, we already have some of the tooling arrival has coincided nicely with an uptick in in place, we’re increasingly being asked to business after a recent suppression following Contact: Gerry Jones support OEM customers with production the UK’s full lockdown in March. Mr Holloway [email protected] volumes – often running into thousands describes the current market conditions as www.trumpf.com
RADAN HELPS COMPANY MEET VENTILATOR ORDER
Sales Manager, Paul Collins, explains they quickly identified ways of adapting to increase manufacturing capacity, including bringing in 35 more people and implementing new shift patterns to move to a 24/5 operating model. He says it also became clear that their RADAN CAD/ CAM software from Hexagon Manufacturing Intelligence would be a key enabler to manage what he describes as a ‘major leap.’
A contractor to the medical industry suddenly He said "we use RADAN to program both our saw its order for Intensive Care ventilator TRUMPF punching machines and TRUMPF components leap from 4,000 a week to over laser cutter, so with over 18,000 components 18,000. And that increase in production looks a week to produce for these ventilators alone, like continuing into early 2021. we knew the material utilisation and program optimisation was going to be crucial to meet Custom enclosure and hardware specialists, such a significant demand." Bolger Engineering, have been manufacturing high quality assemblies and fabrications as a RADAN is also used for generating quotations, trusted partner to their OEM customer base and Collins says they have recently installed for over 40 years. They provide end-to-end Radquote to speed up the quotation process solutions, including full contract manufacturing even more. “Speed of response is critical in and supply chain services across multiple the current environment; Radan software is a verticals. key enabler in allowing us meet current market expectations.” Due to the spread of COVID-19, demand jumped to unprecedented levels, and the customer needed to produce 500 units a week, Contact: Stewart Bint instead of 10, which meant Bolgers needed to [email protected] ramp up their production of individual parts. www.hexagon.com
9 ISSUE 99 WINTER 2021 THE LASER USER
Laser Assisted Machining
10 THE LASER USER ISSUE 99 WINTER 2021
EARLY CAREER RESEARCHERS
WELCOME TO NEW ECR COMMITTEE MEMBERS
SHEONA DAY VINCENT ZHANG TRUMPF UK COVENTRY UNIVERSITY I have just joined TRUMPF Lasers UK as My passion for aeronautics led me to a laser development engineer developing study science by first going to the ESILV novel high power pulsed fibre lasers. I engineering school in Paris where I was joined from Gill R&D, an environmental enrolled in the mechanical engineering sensors company, where I was a Masters. There, I had the chance to research engineer specialising in the partake in a double degree program with development of novel fibre optic-based Coventry University and studied in the sensing techniques. mechanical engineering MSc, writing a thesis on the laser shock peening of I started at Gill directly from the University Zirconia and graduating with distinction. of Southampton, where I studied a Master’s in Physics with an industrial placement. Outside of my day job, I am involved with the IOP’s Early I then moved to Germany, where I worked in the aviation industry for one Careers Member’s Group committee. I look forward to joining the AILU year as integration Engineer on the Airbus A350. I have now started my Early Careers Researcher’s Committee, perhaps creating links between PhD at Coventry University in the Institute of Future Transport and Cities. the two groups. My research focuses on strengthening high performance metal parts produced by additive manufacturing using laser shock peening. [email protected] [email protected]
HOW LASERS HELP REDUCE FOOD WASTE
The real-time multi-gas detector that saves fruit Under Horizon2020, a European consortium is making a new weapon in the fight against fruit waste.The consortium is called MAX-FRESH. It aims to commercialise a sensor that can – simultaneously and in real- time – detect low levels of several volatile gases that indicate ripening, fermentation, damage, or rotting of the stored fruit. This system is the Interactive Storage System-Monitor or the ISS-Monitor. The ISS-Monitor regularly samples the air in the storage rooms and analyses it.
The central analysis unit is a mid-IR supercontinuum white light laser and a spectrometer. The equipment determines the concentration of the gases in the storage room using gas spectroscopy. The fruit owner will get an alarm if the ISS-Monitor detects harmful conditions and can decide to change the storage conditions or sell the fruit.
According to the project description, the ISS-Monitor can potentially reduce the losses of stored fresh food by 50%, extend storage life by 20%, and reduce post-harvest chemical treatments by 50%. This contributes to Today, 33% of fruit and vegetables go to waste before they reach the fulfilling the UN’s Sustainable Development Goal Target of halving food consumer – and 10% of the waste happens during long-term storage. waste by 2030 as well as the EU’s targets to reduce food waste across the Every year, apples, pears, and blueberries alone account for a EUR EU by 2023. 6.1 billion loss globally. The fruit waste also contributes hugely to greenhouse gas emissions because fruit emits methane as it decomposes. Commercialisation of an existing prototype If we could monitor stored fruit continuously, we could prevent as much as The MAX-FRESH team is building a commercial version of the ISS-Monitor 50% of the storage losses. based on a functional prototype that was developed and tested during the Fruit owners keep the fruit in large storage facilities. They typically store QCAP project and funded by InterReg North-West Europe. The ISS-Monitor hundreds of tons of fruit in one room, and they often have 10 to 20 rooms. will be commercially available in 2023. The fruit is stored in a controlled temperature and atmosphere to extend its The MAX-FRESH project team is brought together to combine cutting-edge lifetime. But it is all about balance. If the oxygen level in the storage rooms technologies with unique expertise and consists of an academic partner is too high, the fruit will decay. However, if it is too low, the fruit will start to and three market-leading industrial partners: Radboud University, Senseair, ferment. Storex bv, NKT Photonics A/S.
The key is to keep a close eye on all the gasses that influence the fruit, This project has received funding from the European Union’s Horizon 2020 such as oxygen and carbon dioxide. The owner can optimise the storage research and innovation programme under grant agreement No 958840. conditions by controlling the oxygen and carbon dioxide levels.The level of methanol and ethanol tells the owner of beginning fermentation, rot, or Contact: Tara Murphy fungal infections. Knowing this, the owner can either adjust the storage [email protected] conditions or sell the fruit before it goes bad. www.nktphotonics.com 11 ISSUE 99 WINTER 2021 THE LASER USER INTERVIEWPRODUCT NEWS
MAKING MOTION AND CONTROL EASY FOR THE LASER INDUSTRY AN INTERVIEW WITH CLIFF JOLLIFFE HEAD OF SEGMENT MARKETING INDUSTRIAL AUTOMATION, PHYSIK INSTRUMENTE (PI) UK
Q. Can you tell us a little about Physik Instrumente (PI)?
“It always seems appealed to me when I 1977 the company moved impossible. Until it’s joined PI three years ago. to the Karlsruhe region done”. This knowledge I wanted to support this and has since grown has been the driving force endeavor, focusing even to a global player with behind the daily doing of more on high-precision 1,300 employees and a PI since the foundation industrial automation. turnover of €200 million, of the company, and with 9 manufacturing sites has ensured that it The company originally and 15 sales and service has developed from emerged from the offices in Europe, North a manufacturer of Max Planck Institute America, and Asia. components and for Quantum Optics in nanopositioning devices Garching, Germany, The sales and support to a solution supplier for in 1970. The institute office for UK and motion and positioning worked with lasers and Ireland is situated in the systems with a broad when a higher precision technology park near product portfolio and was required, PI was Cranfield University with technological range. This formed to assist in the 17 staff. new requirements. In 12 12 THE LASER USER ISSUE 99 WINTER 2021
INTERVIEW
Q. How significant is laser processing to your For PI as exhibitor, there is a lot of work to ship heavy and sometimes sensitive demonstration equipment and set it up on site which adds business? time and cost to the process of attending a show. Even before the Originally, the company was driven by exploiting piezo technology pandemic, we were starting to evaluate each show and decide and research always aimed at enhancing the technology of the whether they were really worth doing as measured by return on products to maintain leadership. The focus now is more on investment. the market pull and to have a comprehensive range of different motion and control solutions to meet the requirements of system integrators and OEM in general laser materials processing or Q. Anything new and exciting in the pipeline you can talk about? We have recently launched our IMAS (Integrated Multi-Axis Systems) X-417 platform. Designed specifically for laser applications, it has the benefit of combining stages and motion “It appears that recently there control in a package for rapid configuration, delivery (typically under 4 weeks from order) which cuts out the complexity and lead time is much less uncertainty as of getting new equipment on site for our clients. Even granite and our customers see some light machine base mounting are possible with a fast turnaround. In March, we launched our EtherCAT laser control module that at the end of the tunnel. can make the positional firing of lasers easier to program and achieve. This takes the pain out of some application programming and deals with the latest generation of ultrashort pulse and high frequency pulsing lasers with more flexibility – if needed, it can ” even synchronise to the internal laser source clock. micro-precision applications. The laser processing market is becoming a more important and significant part of the whole organisation strategy, with significant development of product Q. What is the best thing about AILU for you? solutions that the market place has been asking for. I have been amazed over the years by the number of people I don’t know and attending AILU events is a great way for me and my colleagues to be introduced to new application areas, Q. What is the current situation like when new businesses, and to meet parts of the laser community that dealing with both Brexit & COVID ? wouldn’t normally come together.
Since January of this year, like most UK businesses, we have found some operational issues with the shipping process which we needed to deal with on what might be considered as short notice. On the other side of the coin, one hopes that there may be opportunities for UK-based machinery suppliers to export to new regions and take “AILU is the place where new advantage of the global support network PI has built up. information is shared in Where possible, we are working from home and the recently introduced online store and tools to remotely set up systems have bite-sized chunks. been well-timed to remotely support our customer base with a reduced need for “on-site visits” for service and application support. We also have a new UK application centre, which is adjacent to our original building, that reduces the need for our customers to travel ” abroad. Many of our customers are finding “home-working” impossible Although there are benefits in flexibility and ease of access to (e.g., system builders) and there is a mixture of responses to the online events, the networking that happens in the evening over a pandemic depending on the health of research funding and the relative drink or during mealtimes at events like ILAS is something I miss. strength and resilience of markets. It appears that recently there is There is also a danger of information overload, so sometimes much less uncertainty and procrastination in our customers as they AILU is the place where new information is shared in bite-sized see some “light at the end of the tunnel”. chunks and there are opportunities to learn how lasers are being introduced into new applications in a large number of industries. Q. Do you find it good or bad that events like ILAS have had to move online? There are some benefits in researchers presenting online. They are perhaps able to attend more events without the need to beg for travel Contact: Cliff Jolliffe budgets for flights, hotels, and fees with most online events being [email protected] more efficient in time and cost than in-person events. www.pi.ws
13 ISSUE 99 WINTER 2021 THE LASER USER
ANNUAL JOB SHOP BUSINESS MEETING 2020
On 19 November we held the first online AILU MICROMETRIC EXPANDS CUSTOMER BASE WITH NEW Job Shop Business Meeting with the theme STARCUT TUBE SYSTEM of “Survive and Thrive in the 2020s”. This was a morning meeting and finished by lunchtime. Lincoln-based manufacturing firm Micrometric The day started with a welcome from the has introduced Coherent’s StarCut Tube system Chair, Mark Millar of Essex Laser, followed by to its range of cutting equipment. The fully three talks aimed at helping business owners. automated machine is designed to laser cut, Dave MacLellan gave a brief introduction to drill and mark tubular or flat metal components the ways AILU membership can be used to and is traditionally used by subcontract maximise exposure for Job Shop businesses. manufacturers to produce exclusive medical Adam Tyler from FunderFinder detailed the instruments with extremely high precision. access to 140 funding sources available Since investing in this equipment, Micrometric’s through the AILU landing page. Finally Liam workforce have found new uses for this machine Conway from Control Energy Costs (CEC) - the company has been using it to produce talked about reducing energy bills from a Job a flexible range of tube components in large Shop perspective. After these presentations volumes as well as finer, more precise parts for a Dave presented the Annual Breakdown wide range of sectors other than medical. Service Response Survey. aerospace components for companies which Neil Main, Managing Director at Micrometric, produce aerospace filters, automated injection After a short break with breakout rooms said: “The machine´s versatility allows us to cut needles, endoscopy components and MRI for chat, there was an opportunity to catch thinner tubes than our other machines and has scanning equipment. up with the latest new developments from allowed us to extend our capabilities and the II-VI, Mazak, TRUMPF, NSC, ASTES4, MSS, range of customers we can service.” Bystronic and Atlas Copco. Contact: Chris Waters Micrometric has already used the machine to The rest of the meeting which ended [email protected] cut, assemble and weld complex medical, and at lunchtime was spent in a lively open www.micrometric.co.uk discussion related to COVID, Brexit, automation of sorting, investment, tube cutting and business confidence. The WEC GROUP WINS AT APPRENTICESHIP AWARDS UK market was reported to be very busy in terms of installations of new systems WEC Group has achieved major national and automation, with the goal to be more recognition after being crowned as the UK’s competitive and achieve higher efficiency. The Large Employer of the Year at the National CBILS (Coronavirus Business Interruption Apprenticeship Awards 2020. Loan Scheme) has resulted in some added investment. The Awards celebrate the achievements of outstanding apprentices and apprentice employers who champion the benefits of apprenticeships across England. It is one of the most sought-after awards in the training and Contact: Dave MacLellan [email protected] education world, with over 1100 companies www.ailu.org.uk and apprentices applying every year and only Contact: Wayne Wild 10 national winner titles awarded among these [email protected] across an array of categories. www.wec-group.com
14 THE LASER USERUSER ISSUEISSUE 99 99 WINTER WINTER 20212021 CHAIR’S MESSAGE
EYE OF THE STORM
Welcome to 2021! Most of us couldn’t wait for 2020 to be ourselves lucky if the increased steel prices and slight over in the hope that this year will be better. However, right scarcity are the main issues we are contending with. now as I write this, the UK is in the middle of yet another I do worry that we are blissfully ignorant as to what the lockdown, the Coronavirus pandemic is biting pretty hard, short- and long-term implications are going to be as the the numbers are just out of control and added to that, the Pandemic and Brexit combine in the UK. Perhaps they will real world implications of Brexit are starting to come out of create the perfect storm or perhaps we are already past the woodwork. the worst of it. Either way I can’t help feeling like we are in Despite these issues the economy is still ticking along. the eye of the storm as lockdown feels manageable, work Of course there are specific industries which are hurting levels are ticking along for most of us and Brexit is mostly badly; aviation, automotive, high-street retail, hospitality and just annoying the hell out of anyone doing the paperwork for tourism to name just a few. Outside of these though, dare logistics to and from Europe. I say it, it feels almost like business as usual. We have all As we come out of the eye of this storm what we don’t want had many months to get used to the Covid restrictions in to see is that Brexit and the Covid restrictions start to slow the workplace and despite the less-than-helpful government the economy further or inflation starts to increase. I hope rhetoric of “Get ready for Brexit” before anyone knew what instead the pandemic starts to abate and work levels pick the final agreement was actually going to be, most had up further still, especially as those industries I mentioned guessed whether their business was going to be affected or earlier start to return to normal. not. Let us hope we get the vaccines out there as fast as Noticeable developments are the delays at the ports and possible so that some semblance of pre-Covid life can the lack of output from the steel mills. One could argue the return and that this is a better year for us all. Wishing you all steel mills are up to their old tricks of holding up supply to the best for 2021. increase prices, but at the moment it is possible the reduced output is genuinely related to the pandemic. In any case Mark Millar this has led to material being in slightly short supply and pushed prices up quite significantly. To be honest though [email protected] with everything else going on in the world, we should count www.essexlaser.co.uk
Choose a laser gas supplier you can trust
Laser cutting requires consistency, efficiency and productivity. At Air Products we have high purity laser gases. We will work with you to supply the most cost effective delivery mode to minimise waste and ensure flawless quality.
15 ISSUE 99 WINTER 2021 THE LASER USER
HOLLOW CORE FIBRES HOLLOW CORE FIBRES FOR HIGH POWER DELIVERY IN 1 µm REGION HESHAM SAKR ET AL.*
Guiding light in glassy optical fibres is an enabling technological platform supporting a $40 billion global cable market, with over 400 million km of fibre produced every year, which is key for applications in the telecommunications, sensing, defence and medical sectors. The ultimate contender currently forming the basis for the present generation of industrial fibre optics for the telecoms sector, are fibres fabricated with solid cores of silica glasses. Yet, these fibres demonstrate numerous hurdles for applications at shorter wavelengths (e.g. 1 µm). In this article we discuss the advances of our most recent work at the Hollow Core Fibre group, University of Southampton, where we develop hollow (air-guiding) core fibres with Figure 1: Nested Anti-resonant Nodeless Fibre (NANF). (a) scanning electron micrograph cross- losses comparable or lower than achievable in section of a typical fabricated hollow core NANF. (b) microscope image of the transmitted optical solid glass fibres around technologically relevant mode, confined in the air core surrounded by the 6 nested tubes. (c) comparison between start of wavelengths such as 1060 nm. Their low loss pull (SOP) and end of pull (EOP) cross-sections of the fibre, showing the uniformity achieved along air-guiding structure combined with extremely the as-drawn fibre length. (d) and (e) illustrate the terms used in defining the structure. low nonlinearities and high damage threshold, transmission of peak powers exceeding 10s MW Fibre description and characterisation compared to silica fibres, offer the potential for for ns/ps pulses [1], GWs for fs pulses [2], and In Figure 1 we show an example of a fabricated exciting advances in key applications such as kW for CW lasers, but only in a few m length [3]. NANF [4]. Here, a central microstructured high power laser delivery. Reducing the optical losses, which are the main region contains an air core surrounded by 6 nested cylindrical glass membranes that are Background current hurdle in these fibres, is crucial. Our attached to the inside of a glass jacket tube, Utilising fibre optics to handle and deliver high current work explores a new structure called Nested Antiresonant Nodeless Hollow-Core Figure 1(a). The fibre is designed to support a laser energy is of extreme importance for single spatial mode after certain length, Figure applications such as industrial welding, cutting, Fibres (NANF) which in theory offers lower losses than achieved by their counterpart silica fibres 1(b) [8]. The definition of core diameter (D), and heat treating that demands the delivery inter-tube gaps (d), wall thickness (t), primary of laser power to remote locations. For over [4]. In 2019, we reported a NANF designed for the 1 µm region with an optical loss of 2.78 cladding tube (‘outer’) and nested cladding tube 50 years, pure or doped silica glass optical (‘inner’) is shown in Figure1(d-e). These fibres fibres have been an unrivalled platform for the dB/km at 1070 nm [5], ~3x lower loss than that of the state of the art then. With additional are fabricated in our facilities using the stack, transmission of laser light and optical data at fuse, and draw method with highly controllable wavelengths from the visible to the near infrared. improvements on the structure, this optical attenuation was then further reduced by 50% processes allowing almost indistinguishable Rayleigh scattering, arising from frozen-in density cross sections between start of pull (SOP) and fluctuations in the glass, fundamentally limits the to a minimum loss of 1.23±0.03 dB/km at both wavelengths 1070 nm and 1100 nm [6]. end of pull (EOP), Figure 1(c). We develop fibre minimum attenuation of these fibres and hence lengths of ranges from 400 – 4000 m or longer. restricts their application, especially at shorter Our most recent results show progress in this For in-detail structural dimensions of these fibres wavelengths. range, taking the losses down to 0.55 dB/km please refer to [7]. at 1070 nm [7], to the best of our knowledge Replacing the solid glass core of a conventional A well-known method called ‘cutback optical fibre with a vacuum or gas filled core of the lowest loss reported in an HCF at these wavelengths, and is a great challenge to the measurements’ is used to evaluate the optical a hollow core fibre (HCF) offers a potential way transmission spectra and the attenuation of this to overcome this insoluble attenuation limit set Rayleigh scattering loss of silica fibres at these wavelengths. fibre (see [7]) and are shown in Figure 2. This by the glass’s scattering, but requires reduction fibre transmits across the wavelength range 950 of all the other loss-inducing mechanisms. In this article we review these results which leave – 1207 nm, with losses of 0.52 ± 0.05 dB/km Guiding light in hollow (air) core fibres results in significant margin for improvement and have the at 1064 nm and 0.5 ± 0.05 dB/km at 1100 nm, an ultralow nonlinear response, low glass-mode potential to revolutionise this area of applications respectively. The fibre has a bandwidth of 176 overlap based on fibre design, high damage given their ultralow nonlinearity and high power nm with loss ≤ 1 dB/km between 1006 – 1182 threshold and faster propagation speeds, threshold levels. Please note that all figures in nm and a 230 nm region with loss ≤ 2 dB/km, opening the route for these fibres to be the this article are originally published and depicted between the wavelengths 966 – 1196 nm [7]. ultimate go-to for high power laser delivery in Sakr et al. [7]. applications in the key 1 µm wavelength region. To contextualise the loss of the fibre, in Figure 3 This has already been demonstrated in the we plot them in the same graph with state-of- 16 THE LASER USER ISSUE 99 WINTER 2021
HOLLOW CORE FIBRES
due to self-focusing and dielectric breakdown of the glass [9]. Transmission of more than a kW of average power from a CW laser has also been reported in HCFs, although only over a few m [3]. Combining the ultra-low loss reported here (0.52 dB/km at 1064 nm, which could be reduced further) with other unique properties of air-guiding fibres could in principle enable kW power delivery in a single spatial mode over a significantly longer transmission range, potentially up to several km. This has the potential to extend the application areas for high power Figure 2: Structure and transmission properties of the reported fibres: Left, SEM images illustrating laser sources, enabling, for example, distribution the structure. Middle, transmission spectra of long and short lengths of the fibres. Right, measured of laser power to multiple workstations in a cutback spectra at the relevant antiresonance passband. manufacturing plant, or deep subsurface rock drilling for exploration of oil, gas and geothermal energy resources.
Conclusion In conclusion, thanks to combined efforts of our team at the Hollow Core Optical Fibre group, University of Southampton, we have demonstrated an optical waveguiding technology that can outperform solid core silica fibres at the key wavelength region of 1 µm which numerous applications such as cutting, welding, drilling and marking could greatly benefit from.
References [1] P. Jaworski, et al. Opt. Express 21, 22742–22753 (2013).
[2] S. Eilzer & B. Wedel, Fibers 6, 1–11 (2018).
[3] G. Palma-Vega, et al. "High average power transmission through hollow-core fibers," in In OSA Laser Congress 2018 (ASSL) (2018), paper ATh1A.7.
[4] F. Poletti, Opt. Express 22, 23807 (2014).
[5] H. Sakr et al., in 2019 Conference on Lasers & Electro-Optics / Europe and European Quantum Electronics Conference (CLEO® / Europe-EQEC) , Munich 2019 (2019), Paper CE-5.5.
[6] H. Sakr et al., in OSA Advanced Photonics Figure 3: Loss of NANFs reported in this work. NANF-A operating at 1060 nm (solid red). The Congress, Speciality Optical Fibers (2020), p. Paper shaded yellow band represents the fundamental Rayleigh scattering loss of state-of-the-art solid SoW1H.5. core fibres [10]. The yellow circular markers indicate the typical loss of commercial solid core single [7] H. Sakr et al. Nat. Commun. 11, 1–10 (2020). mode high numerical aperture fibre for 980 nm pump delivery (Corning® HI 1060 Specialty Optical [8] H. Sakr et al. in OFC, Paper PDP TH4A.1 (2019). Fibers). The blue diamond markers represent the current state-of-the-art loss in hollow core fibres [9] A. V Smith & B. T. Do, Appl. Opt. 47, 4812–4832 [11]. (2008).
[10] Nagayama et al. Electron. Lett. 38, 1168–1169 the-art reported loss values from other optical Ytterbium fibre lasers are extensively used for (2002) fibre technologies. The shaded yellow band cutting, welding, drilling and marking, hollow [11] Maurel et al. Opt. Lett. 43, 1598–1601 (2018) represents the fundamental Rayleigh scattering core fibres are already enabling power delivery loss of state-of-the-art solid core fibres (for more at transmission distances and power levels not details refer to [7]). possible with solid fibres. *Hesham Sakr, Yong Chen, Gregory Jasion, Thomas Bradley, John Hayes, For pulsed laser sources, the low nonlinearity Discussion Hans Christian Mulvad, Ian Davidson, Eric and high damage threshold of HCFs have In this work, we have shown that through good Numkam Fokoua, Francesco Poletti already enabled transmission of peak powers understanding of the loss mechanisms in hollow exceeding 10s MW for ns/ps pulses [1] and Contact: Hesham Sakr core fibres, choice of an appropriate structure – GWs for fs pulses [2], which would cause [email protected] the NANF – careful control of design parameters catastrophic damage in an all-solid optical fibre hcf.soton.ac.uk and fabrication procedures, air-guiding fibres with loss comparable to, and in some cases lower than achievable in a solid core fibre can be Hesham Sakr is a Research Fellow with the Hollow- realised at a range of wavelengths around 1100 nm. Core Fibre group, Uni. of Southampton. His research areas are in fibre optics, photonics, and glass materials. In the waveband between 1030 and 1090 nm where Nd:YAG lasers, Yb:YAG disk lasers and SEE OBSERVATIONS P26 17 ISSUE 99 WINTER 2021 THE LASER USER
SURFACE TEXTURING INTERFERENCE PATTERNING OF METALLIC SUBSTRATES PETR HAUSCHWITZ
Laser surface patterning is a well-known method for modifying surface properties by introducing surface features, usually of a micro to nanoscale size. However, long processing time is still the main drawback for industrial applications. The newly emerging kW-class ultrashort laser systems in combination with a suitable multi-beam technology - such as direct laser interference patterning (DLIP) with enlarged beam - can offer high precision and localised cold ablation of ultrashort pulses together with high throughputs. Figure 1: Illustration of experimental setup with marked shift between interference and focal plane and with the inset of elongated spot shape fabricated on stainless steel sample [7]. Fabrication of functional surfaces with micro and nanostructures is a very popular topic in science The interference pattern can be controlled by laser system. The beam divergence was tuned and industry. Surface functional performance, the polarisation, number of laser beams and with the goal to reach a major ellipse diameter inspired by nature, often originates in hierarchical their incidence angle as well as by wavelength, ~1 mm. The interference area diameter on the structures composed of micro- and nano-scale intensity and phase difference. However, lenses sample can be further tuned by the pulse energy features assembled into complex structures [1]. with short focal length are necessary for the and number of pulses, as depicted in Figure 2. Among different types of structures, strategies high incident angle of interfering beams to reach The largest major diameter of 1.40 mm was for fabrication of multi-scale systems have been micron-sized pattern periodicity. Consequently, achieved for invar irradiated with 3 mJ and 1000 most extensively investigated. Such structures potential throughputs are limited by the diameter consecutive laser pulses. With the same laser can enhance or completely modify original of interference area, which is often in the order of parameters, the major diameter of stainless surface properties to reach anti-icing, anti- a few tens of microns [6]. corrosion, anti-bacteria or superhydrophobic steel and tungsten was 1.28 mm and 1.15 mm, respectively. properties [2]. Improvements at HiLASE Among a large variety of techniques for To increase the throughputs, a large-beam Several different surface morphologies replicating naturally occurring microstructures, interference technique was developed at HiLASE can be achieved by the variation of pulse laser surface texturing provides a flexible, fast [7]. The divergence of the initial laser beam was energy and the number of applied pulses. and environmentally friendly approach for high modified by telescope causing a shift between Generally, three different surface morphologies precision fabrication of desired micro and the interference plane and the focal plane. This were demonstrated on each material. Low nanogeometries [3]. However, the commonly elongated the interference area and reshaped spatial frequency laser-induced periodic used direct laser writing technique, utilising only it into an elliptical area due to the high angle θ surface structures were produced only at one laser beam in a combination with galvo (Figure 1). interference maxima positions. Thus with adjustable separation distance following the scanner, may not satisfy high industry demands However, to apply this technique, several interference period (Figure 3a,d,g), line-like for treatment of a large area in a short time. requirements have to be fulfilled. Laser systems trenches with the periodicity of interference This is especially difficult to fulfil in the case have to provide high enough pulse energy to pattern covered by nanoscale protrusions of high-resolution micron scale structuring. reach fluences above the ablation threshold in (Figure 3b,e,h). Conical-shaped micropillars Additionally, the increase in average power of each interference maxima. Another requirement the ultrashort laser systems in recent years [4] is connected with the pulse duration, which limits will not be reflected in the effectiveness of micro the maximal possible area of interference and a and nanoprocessing, because only a small minimal achievable detail of structures defined percentage of available laser power is used for by the heat diffusion length [7]. The HiLASE processing to avoid melting and thermal effects. Perla laser system fulfills these requirements, producing up to 20 mJ with a pulse duration Interference patterning of 1.7 ps, resulting in the theoretical limit for Direct laser interference patterning (DLIP) interference area of 2.6 mm together with heat provides a solution to these issues by diffusion length below 12 nm. overlapping two or more coherent laser beams on the substrate in order to directly imprint an Interference processing of metallic interference pattern on its surface. If enough substrates pulse energy is used, a large variety of materials Different metallic materials, including stainless can be patterned on the surface area, in the steel 316L, tungsten and invar (FeNi36), were Figure 2: Major diameter of interference area order of several tens of µm in diameter in a used to prove the concept of large-beam showing a dependence on pulse energy. single irradiation step, and with resolutions interference patterning utilising the HiLASE Perla below the diffraction limit of the initial beam [5]. Samples are irradiated by 1000 pulses [7]. 18 THE LASER USER ISSUE 99 WINTER 2021
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experiment, with a 1 kHz high-energy pulsed laser source, demonstrated the fabrication of a variety of micro- and nano-structures with throughputs up to 206 cm2/min. This may be further scaled up either by the repetition rate or by the increase in interference area to reach more than 1 m2/min.
References [1] Liu, K. & L. Jiang. Nano Today, 2011, 6(2), 155-175. [2] Malshe, A. P. et al. CIRP Annals, 2018, 67(2), 627-650. [3] Liu, X. et al. IEEE journal of quantum electronics, 1997, 33(10), 1706-1716. [4] Smrž, M. et al. Applied Sciences, 2017, 7(10), 1016. [5] Lasagni, A. F. et al. In Laser-based micro- and nanoprocessing XI. International Society for Optics and Photonics, 2017, vol. 10092, p. 1009211. [6] Aguilar-Morales, A. I. et al. Journal of Figure 3. Different surface morphologies achieved by variations in pulse energy and Materials Processing Technology, 2018, 252, number of pulses (N) [7]. 313-321. [7] Hauschwitz, P. et al. Materials, 2020, 13(20), formed due to melt flow driven by thermal Summary 4676. gradients caused by inhomogeneous energy The growing industry demand for fast and distribution induced by surface geometry (Figure reliable micro and nanostructuring can 3c,f). In the case of tungsten, melting and be satisfied by sophisticated multi-beam structure collapse instead of the formation of micromachining approaches, including direct Contact: Petr Hauschwitz micropillars was observed (Figure 3i). laser interference patterning with enlarged [email protected] In addition, by applying a low number of interference area. The proof of concept www.hilase.cz pulses, high spatial frequency laser induced periodic surface structures were achieved on stainless steel and invar (Figure 4a,b). In the case of tungsten, a different kind of structure was produced. The material appeared to have melted, with random nanostructures originating from rapid melting and melt ejections towards the laser source, followed by quick resolidification forming a randomly organised nanopillars with dimensions below 100 nm (Figure 4c).
The fabrication speed of the introduced large- Figure 4. HSFL and nanopillars achieved by single pulse irradiation of (a) stainless steel, beam interference patterning technique reached (b) invar and (c) tungsten [7]. 0.34 cm2/min (1000 consecutive pulses) and 206 cm2/min (single pulse). Considering 1 kHz repetition rate of used laser system, these throughputs may be scaled up in orders of magnitude together with the repetition rate.
To demonstrate the potential as a functional surface, the wettability was tested. Tests were performed on all materials covered by line-like trenches with the periodicity of 2.6 µm, further covered by nanoscale protrusions (Figure 3b,e,h). Figure 5. Wettability measurements of laser processed samples after vacuum treatment [7]. All samples were found to be superhydrophobic with contact angles of 164°, 156°, 150° for stainless steel, invar and tungsten respectively as shown in the Figure 5. Thus, this technique Petr Hauschwitz leader of laser micromachining group demonstrates capabilities for rapid large-scale at HiLASE Centre. His research interests include surface surface functionalisation. functionalisation and multi-beam micromachining.
SEE OBSERVATIONS P26 19 ISSUE 99 WINTER 2021 THE LASER USER SURFACE TEXTURING SURFACE STRUCTURES MITIGATE BACTERIAL ADHESION ANVESH GADDAM ET AL.*
Hospital-acquired infections due to pathogenic bacteria cause significant human and economic losses worldwide [1]. In general, bacterial growth occurs on surfaces of various indwelling medical devices and non-implantable objects in hospitals. Although the existing silver nanoparticle-based coatings are effective in imparting bactericidal properties, the increased antibiotic resistance due to these coatings poses a major concern [2]. Therefore, there is a need to design eco- friendly functional surfaces that inhibit bacterial adhesion. One way to mitigate the bacterial adhesion is by reducing the contact area for the bacteria on a surface through surface texturing. Since the typical size of cocci (spherical-shaped) and bacillus (rod-shaped) bacteria cells is 0.5 – 2 µm, the surface textures should have a characteristic dimension in the sub- micron range for inducing an anti-biofouling response. Figure 1: SEM micrographs of highly regular LIPSS on (a) SS, (b) PDMS and (c) PU. (d-f) AFM Likewise, because elastomers such as silicones micrographs of the LIPSS on (d) SS, (e) PDMS and (f) PU. (g) A plot showing height profiles of the and urethanes are ubiquitous in medical devices, LIPSS on SS, PDMS and PU. it is essential to cost-effectively fabricate and Polyurethane (PU) elastomers. In addition shown in Figure 1g indicate excellent replication. sub-micron topographies on such materials. to the replicated LIPSS and MS topographies, The replication efficiency was estimated to be The so-called laser-induced periodic surface the lubricant-impregnated surfaces were also 87% for PDMS and 93% for PU. structures (LIPSS), which have a characteristic produced to compare the effectiveness of the periodicity in the sub-micron range, can be The 3D images from the focus variation anti-biofouling response. produced on metallic masters. The LIPSS microscope on all three substrates are shown topographies in turn could be replicated on the All the textured metallic and elastomeric in Figure 2a-c showing replication quality. The elastomer surfaces through technologies such substrates were characterised using ESEM, replication efficiency for the MS topographies as injection or compression moulding for mass Focus Variation Microscope (Alicona G5), was more than 95%. The SEM micrographs production. In this work, we fabricated the LIPSS Spinning Disc Confocal Microscopy and AFM. of the MS topographies on SS and elastomer topographies on stainless steel masters and then While the optical characterisation was conducted substrates in Figure 2e-f indicate that the LIPSS replicated them on elastomers to investigate the with a UV-Vis spectrometer, the wettability of covering micron scale protrusions were excellently anti-biofouling response. textured surfaces were examined with a contact replicated. The sub-micron ripples in the MS angle goniometer. Bacterial adhesion tests were topographies also have a depth of 100-200 nm. Methodology performed on all substrates with rod-shaped Since the elastomeric surfaces are continuously We used AISI 430 (X6Cr17) ferritic stainless steel gram-negative bacteria. The Escherichia coli exposed to bodily fluids and medicinal liquids in (SS) plates for producing the textured masters. BL21 (DE3) strain was selected as a model hospital environments, the physicomechanical A LASEA LS5 workstation that integrates a bacteria in this research because of its wide use integrity of sub-micron topographies under Yb-doped femtosecond laser source (Satsuma, in investigations on the antimicrobial efficacy of long-term exposures (~100 hours) to liquids was Amplitude Systemes) with a wavelength of 1032 textured surfaces. investigated. The MS topographies substantially nm, a pulse duration of 310 fs, an average power increased the static contact angle of the of 5 W and a maximum pulse repetition rate of Results surfaces on all the substrates when compared 500 kHz has been employed to fabricate the Figure 1 shows the geometrical characterisation to the LIPSS topographies. Overall, the change textured masters. Two types of textured surfaces results from SEM and AFM of the highly regular in the static contact angles on textured surfaces were fabricated on SS substrates. In the first LIPSS topographies on SS, PDMS and PU. The was less than 7% and 13% on PU for PDMS case, highly regular and single scale LIPSS were periodicity of the LIPSS as evaluated by 2D-FFT replicas, respectively, over a period of 100 fabricated, while in the second case, multiscale (inset of Figure 1a) is 800-900 nm, which is hours. Thus, it is evident that the degradation (MS) textures consisting of LIPSS superimposed close to the wavelength of the laser. The average of physicomechanical properties of the textured on micron-scale protrusions were fabricated. The height of the LIPSS was in the range from 100 to elastomers is not significant. Consequently, textured SS substrates were used as masters 200 nm on both SS and elastomer surfaces. The it is expected that the fabricated sub-micron for soft moulding of Polydimethylsiloxane (PDMS) AFM depth profiles of SS, PDMS and PU LIPSS topographies are durable for a sufficiently long 20 20 THE LASER USER ISSUE 99 WINTER 2021 SURFACE TEXTURING
Figure 2: 3D profiles of the MS topographies of (a) SS, (b) PDMS and Figure 3: The illustrations of bacteria on different surfaces is shown (above). The (c) PU. (d) A plot showing height profiles of micron scale protrusions contact points of bacteria on a surface is highlighted in red in these images. The in different directions. (e) SEM micrograph of the MS topography on fluorescence micrographs showing bacteria adhesion on plain, LIPSS, MS and SS. (f) SEM image showing the LIPSS on micron scale protrusions of LIS topographies of PDMS and PU (below). (scale bar - 25 μm). the MS topography on a PDMS replica. time in biomedical operating conditions. shown to reduce adhesion of bacteria by more performance would be severely compromised than 95%, the functionality of such surfaces is on such sub-micron topographies if round- In addition to the physicomechanical integrity, short-lived. This is because lubricant present shaped bacteria were used, as they would the optical transparency is also a requirement on the LIS can leach over a period of time into require a much lower degree of surface contact for elastomers in biomedical devices. Therefore, the working liquids and pose contamination for a successful adhesion when compared UV-Vis spectra measurements were obtained issues in biomedical applications. Therefore, to the rod-shaped bacteria. Therefore, LIPSS in 400-700 nm to understand the detrimental highly durable LIPSS or MS topographies can be with periodicities less than 600 nm would be effects of surface texturing on the transmittance suitable for such applications. necessary in order to inhibit adhesion for both of the LIPSS and MS topographies. The PDMS bacteria. This could be achieved by varying and PU surfaces have exhibited more than 90% In addition, the LIPSS topographies are optically the laser processing settings, such as laser transmittance. While the LIPSS topographies transparent as compared to MS topographies. wavelength, incidence angle and fluence. marginally reduced the transmittance, the MS However, in reality, fabrication of the LIPSS topographies on both elastomers have greater topographies is sensitive to laser processing Conclusion influence (of about 15%) on optical transparency. disturbances and substrate’s surface roughness Surface texturing at sub-micron scale is a when compared to the MS topographies. To determine the anti-biofouling performance safe-by-design approach to prevent bacterial Furthermore, the presence of any small number of the functionalised elastomer surfaces, the fouling, thereby improving biocompatibility of physical defects on the LIPSS topographies adhesion tests with the E.coli bacterial strain of biomaterials. It is demonstrated that the due to wear leads to local adhesion of bacteria, were conducted. Results showed that a large femtosecond laser-induced sub-micron thus, compromising their anti-fouling properties. number of bacteria adhered to plain surfaces on topographies on silicone and urethane Therefore, the fabrication aspects such as both the elastomers (Figure 3). The textured and elastomers can induce anti-biofouling properties. uniform coverage, reproducibility, abrasion LIS topographies on both PDMS and PU showed Laser processing of masters and fabrication of resistance and replication efficiency need a significant reduction in bacterial adhesion medical packaging products through injection/ attention in the case of LIPSS. Altogether, on them. The reduction in bacterial adhesion compression moulding is a cost-effective considering the indicators such as a better on highly regular LIPSS with respect to plain manufacturing process chain to “imprint” hydrophobicity, less surface defects and surface is 96.7% and 96.1% for PDMS and PU, functionalities on synthetic polymer surfaces. reasonable transparency, despite the high respectively. Whereas, the MS topographies on processing time, the MS topographies are better PDMS and PU exhibited a reduction of 91.1% References candidates than the highly regular LIPSS for and 89.2% in bacterial adhesion, respectively. [1] Adlhart, C. et al. 2018. Journal of Hospital elastomeric surfaces. Upon the application of the bacterial suspension Infection, 99(3), pp.239-249. on the textured surfaces, the bacteria was It is important to note that the mean feature size [2] Panáček, A. et al. 2018. Nature brought into contact with the sub-micron of the sub-micron topographies should be less nanotechnology, 13(1), pp.65-71. topographies (Figure 3). As a result, the decrease than the typical sizes of the bacteria to achieve in bacteria-accessible area on LIPSS and MS the required anti-biofouling response. The NIR *Anvesh Gaddam, Reshma Yasmin surfaces when compared to the plain ones, led laser used in this research produced sub-micron Siddiquie, Amit Agrawal, Stefan S Dimov, to a reduction in adhesion. Since the contact topographies with periodicities in the range of Suhas S Joshi area on the MS topography was more effective 800 – 900 nm, which were less than the size of The authors acknowledge the financial support of in regards to the bacteria suspension than the the rod-shaped E. coli bacteria (typical length the UKIERI-DST (DST/INT/UK/P-169/2017) project. LIPSS topography, the former exhibited a slightly of 1.5 - 2 μm). At the same time, the typical increased bacterial retention than the latter. diameter of the most round-shaped bacteria, Contact: Anvesh Gaddam e.g. Staphylococcus spp. and S. aureus, ranges [email protected] Discussion from 0.5 to 1 μm. Therefore, the anti-biofouling www.bham.ac.uk Overall, the LIPSS and MS topographies reduced the adhesion of bacteria by more than 89% on both the elastomers. At the same time, the sub- micron textured elastomers exhibited reasonably Anvesh Gaddam is a Research Fellow in Advanced good durability over long term exposure to Manufacturing Technology Center at the University of water. Therefore, their anti-biofouling efficacy Birmingham. will be least affected by continuous utilisation in biomedical applications. Although the LIS have SEE OBSERVATIONS P26 21 ISSUE 99 WINTER 2021 THE LASER USER LASER ABLATION
DOWN TO THE WIRE – LASER ABLATION OF MEDICAL MICRO WIRES OLIVIA GILLEN & MICHAEL O’DONNELL
In early 2020, Fort Wayne Metals, Indiana, challenged Blueacre Technology to develop a solution for micro wire stripping that would meet the needs of its customers. Despite the turmoil and restrictions of lockdown, Blueacre Technology engineers designed and built a bespoke laser system to meet these most exacting requirements.
The Challenge Fort Wayne Metals produces wires made out of a range of materials, including stainless steel, nitinol, titanium and high performance alloys. For many applications these wires need to be Figure 1: Silver coated copper wire with kapton insulator coated. The coating is an important part of the wire’s functionality, and the coating material reflects the functionality required, whether it be for conductivity or insulation, chemical separation or lubricity. There might be one layer, or there might be several, and the thickness of each layer can vary from 200 nm to 1 µm. Coatings include metals such as platinum, silver or gold and fluoropolymers such as ETFE, PFA, FEP and PTFE.
The wires need the functionality provided by their coatings for specialised medical applications such as guidewires, implants and nerve or brain stimulation devices. Once coated, for some applications the coating then needs to be stripped at various points along the wire. The wire must remain clean and undamaged, and the locations where the coating is stripped needs to be ultra-precise. This is a challenge, particularly for ultra-fine wires such as those used for applications inside the human brain.
Where there are several layers it may be Figure 2: Micro wire compared with a standard electrical wire necessary to remove one layer, such as an insulation layer, while leaving another underlying compared to the size of the overall part and will this is where laser technology comes in. layer of coating intact. not pose significant quality issues. As well as the non-contact nature of the Adding to the complexity of the task, the wires However, as the diameter of the wire gets process, laser processing also grants the ability being stripped are extremely fine, as small as 0.3 smaller and the coating layers get thinner - to accurately control the laser energy, enabling mm in diameter. To give an idea of how small as with Fort Wayne Metal’s advanced wire tailored stripping with high levels of precision and these types of wires can get Figure 1 compares products - there is substantial risk to wire accuracy. a micro wire with coating to a standard coated damage from a purely mechanical stripping electrical wire and ball point pen. process. In an industry where precision and A flexible solution accuracy are literally life-and-death matters, a As mentioned above, the wires and coatings Why use laser processing? potentially damaged or broken wire presents an manufactured by Fort Wayne Metals come in A typical wire stripping exercise – akin to unacceptable level of risk. an infinite variety of materials, diameters and stripping the ends of electrical cables in the lengths. The solution needed to be able to home - uses mechanical methods, which are The next step up from wire strippers is handle the following variables: ultimately a more sophisticated version of mechanical grinding using diamond discs or our trusty home wire strippers. This will work chemical etching, but these methods also risk • Varying wire diameters, from 0.3 mm to 1 mm. for standard gauge wire. For larger gauge damaging the underlying material. The key to • A variety of materials: the system needed to wires a small scratch or nick is insubstantial avoiding damage is a non-contact process, and work with wires made from stainless steel, 22 THE LASER USER ISSUE 99 WINTER 2021 LASER ABLATION
patterns, depth and lengths of the cut, enabling highly tailored removal.
Successful trials Once the system was built, it was verified and validated for ISO 9000 and ISO 13485 (medical devices) by processing a batch of wires which were tested by Fort Wayne Metals to ensure they met their strict quality requirements. Feedback and fine-tuning enabled further enhancements Figure 3 : High quality laser striping with zero damage to either the PTFE or metal wire. and improvements.
Summary Blueacre Tecnology had previously been asked to handle laser ablation, or stripping of wires, but the project described in this article was of a whole new level of magnitude. Choice and deployment of the right laser type was only the beginning for this type of challenge. Factors of equal importance were:
• How the materials were handled. • How to create a process that was tailored and flexible but also locked down from a quality perspective. • How to achieve predictability and uniformity in medical devices.
The best laser technology is only as good as the Figure 4 : Laser processing spectrum process and system in which it is deployed.
Co-author Michael O’Donnell is Managing high performance alloys, nitinol, titanium and hit the “sweet spot” of price and functionality. Director of Fort Wayne Metals, Ireland, even precious metals. manufacturer of wire products for medical To handle high throughput, Blueacre applications. • A range of coatings: the coatings for the Technology’s system can process up to 50 wires wires are different colours and contain at the same time, precision rotating the wires Contact: Olivia Gillen different blends of polymers. Each of these as the laser modules strip the wires according [email protected] will react differently to the laser beam, and so to the pre-programmed “recipe” governing the www.blueacretechnology.com expert knowledge is needed to manage the laser process. • Differing patterns of coating removal: some wires needed coatings removed at the ends, some at regular or irregular intervals along the length of the wire.
These variables meant that no one type of laser would work in all situations. Blueacre Technology built a proprietary laser system with multiple “plug and play” laser modules, all managed from a central control centre that is programmed to meet the parameters needed. In-line machine vision systems accurately align the laser beam to the wire. Movement of the wire is controlled by high end linear tables, capable of sub-micron accuracy.
A cost-effective solution While this is a high precision and technically demanding requirement, the devices the Figure 5: High throughput precision wire stripping. wires are deployed in are usually single-use, disposable devices, so the solution needed to be high throughput, and low cost but with zero Olivia Gillen is Commercial Director of Blueacre compromise on quality. This also impacted on Technology, provider of specialist laser micromachining the choice of laser source: neither the most services to the global medical device industry. expensive femto laser, nor the cheapest CO2 laser would fit the bill – the choice of laser had to SEE OBSERVATIONS P26 23 ISSUE 99 WINTER 2021 THE LASER USER LASER WELDING LASER WELDING: HIGH VOLUME MANUFACTURING FOR E-MOBILITY PASQUALE FRANCIOSA ET AL.*
Motivated by the growth of the e-mobility simulations [3]. These tools promise improved factors in driving the functional performances of sector and the fact that large arrays productivity and quality (towards zero- the weld. of welds are required for each finished defect), optimised energy consumption and Latest advancements in Optical Coherence assembly, we review some of the reduced scrap. Rather than relying entirely on Tomography (OCT) have shown promise in the most established and adopted sensor the open-loop nature of traditional welding direct measurement of weld penetration depth technologies and closed-loop control process development, autonomous production (Figure 2 shows typical OCT signals). Results in strategies for laser beam welding. We systems leverage a number of digital twin [4] showed that the OCT sensor was capable also discuss current challenges and future assets which gather in-process data and in of direct measurement of the weld penetration perspectives towards the full digitalisation real-time, and provide continuous feedback depth with an accuracy within 100 µm. However, of laser beam welding, in line with the information for “predictive” decision making. the study concluded that the accuracy was current trend of Industry 4.0. Sensor technologies play a pivotal role since highly sensitive to the selection of the welding they serve as the “surveillant” of a process. process parameters. As such, the sensor Laser welding in e-mobility: the situation The need for sensor technologies is very timely required re-calibration every time any process today indeed for the explosive growth of e-mobility parameter was altered. Laser Beam Welding (LBW) currently covers where large number of joints are generated for between 60%-80% of all joining for e-mobility each assembly. While LBW has been rapidly The sensitivity to welding process parameters manufacturing, for high-volume production above absorbed by the industry, the sensor technology is overcome by sensors that passively observe 150k vehicles/year [1]. Typical battery systems itself is lagging for Industry 4.0 requirements, process emissions. Photodiodes are the most comprise hairpins, contact and terminals, bus- especially when it comes to providing closed- established sensors in this category. While bars, modules/pack and enclosures. These loop feedback. photodiode-based monitoring has been largely are complex assemblies that involve multiple implemented for structural welds, applications for layers of dissimilar materials (copper, aluminium, Weld quality and sensor technology welding of thin foils and dissimilar metals remain nickel, steel) with a wide range of thicknesses The quality of laser weldments is assessed an uncharted area of investigation. (from tens of microns to few millimetres), by measuring multiple features such as: (1) We have recently demonstrated that both part- and multiple fabrication processes (forming, surface features – for example, melt pool width, to-part gap and laser power variations can be casting, extrusion). The high flexibility of current concavity, convexity; and, (2) sub-surface diagnosed by observing the step-change in LBW technologies allows the introduction of features – for example, depth of fusion, interface the plasma signal. However, these results have sophisticated welding patterns, fast beam width, weld pores and cracks. Figure 1 shows limitations due to the fact that the photodiodes re-positioning, laser power modulation and beam the typical weld defects that are encountered only provide indirect measurements in the form shaping. The combination of these features whilst welding similar and dissimilar materials. of correlated signals (plasma, temperature and has proved successful to weld challenging Direct measurement of surface features is back-reflection) to the actual welding features. materials, such as non-ferrous alloys and highly well-established, whereas direct measurement This is exemplified in Figure 3 (class [1]: lack of reflective materials. The manufacturing of each of sub-surface features remains an unsolved bonding; class [2]: over-penetrated weld; class battery pack requires joining a large number of problem. Sub-surface features are important [3]: sound weld). Though the correlation between connections - up to 20,000. One single defective weld can cause the scrapping of the whole battery pack [2]. Re-welding of a defective weld, though possible, increases the tendency of crack formation and brittle intermetallics - the latter applies especially to dissimilar material welding.
Monitoring and control of the weld quality can significantly reduce scrap rate. Additionally, control strategies can help to increase weld durability and prevent weld degradation. It is clear that the classic 6-sigma approach currently in use in automotive industry for quality control must be revisited to accommodate for a zero- defect manufacturing strategy.
Autonomous assembly systems: where do we stand with laser beam welding? There is undoubtedly a gradual transition towards autonomous assembly and welding systems, assisted by tools from Industry 4.0 such as Machine Learning (ML)/Artificial Intelligence (AI) and computer-aided physical Figure 1: Example of defective welds. 24 24 THE LASER USER ISSUE 99 WINTER 2021 LASER WELDING
Figure 2: Typical signal generated by OCT technology. Adapted from [8] plasma and depth of fusion is approximately characterise un-trained 90% and the cases with over-penetrated welds cases with a large variety of are well diagnosed (i.e., weld (5) and (6)), this is material property profiles and not sufficient to provide a full diagnosis of weld product variants. Figure 3. Example of process monitoring via photodiode-based defects. For instance, weld (1) – clear lack of • While ML/AI-based models signal (200 µm Cu to 300 µm steel). (a) plasma signal; (b) weld bonding but total fusion of the bottom plate – have shown outstanding fusion depth measured via metallographic analysis; (c) process shows comparable level of plasma generated in performances towards the parameters mapped against plasma signal; (d) representative weld (2) – which is a sound weld. Additionally, generation of actionable cross-sections. determining the correlation demands lengthy models for adaptive control, metallographic analyses, which incur significant they fail to explain the monitoring and adaptive feedback control of cost and manual labour. causality between input process multiple weld features. Further developments parameters and outputs variables. are expected in the coming years that will pave Feedback control systems the way towards full digitalisation of the LBW The aforementioned challenges could be Single-feature control systems have been technology in line with the current trend of overcome by model-driven controllers which, commonly used for the control of LBW, where Industry 4.0 and Industrial Internet of Things. rather than inferring the control law from a either the laser power or the focal position “black-box” data-driven model, make direct is used as control parameter to maintain a References use of the first-principle physical equations. reference value of the depth of fusion [5]. Other [1] T. Sun et al. Procedia CIRP, 2020, vol. 94, pp. Applications of physics-based controllers have examples are seam tracking and gap bridging 565–570. been rarely reported owing to the inherent control systems that cope with the intrinsic [2] M. F. R. Zwicker et al. J. Adv. Join. Process., highly complex underlying physical phenomena vol. 1, no. March, p. 100017, 2020. manufacturing tolerances (i.e., gap and trim involved in LBW [7] and the prohibitive amounts [3] P. Franciosa et al. CIRP Ann., vol. 69, no. 1, edge variation). However, irrespective of the of computational power required to solve pp. 369–372, Jan. 2020. material quality and manufacturing tolerances, the model. Computational delays can affect [4] M. Sokolov et al. J. Laser Appl., vol. 33, no. the LBW system needs to be manually the spatial and temporal resolution of the 1, p. 12028, Feb. 2021. re-optimised and re-calibrated every time a new monitoring device, and the stability of the control [5] A. Blug et al. Phys. Procedia, vol. 12, no. scenario is introduced (i.e., new material alloy, architecture. PART 1, pp. 720–729, 2011. part geometry, processing conditions, etc.). This [6] G. Masinelli et al. IEEE Access, vol. 8, pp. incurs costly and lengthy optimisation loops. Future perspectives 103803–103814, 2020. [7] M. Dal & R. Fabbro, Opt. Laser Technol., vol. ML/AI principles offer the tools to overcome Novel methodologies and technologies are 78, pp. 2–14, 2016. current limitations and set-up automated urgently needed to elevate current laser [8] M. Sokolov et al. J. Laser Appl., vol. 32, no. feedback control systems. Despite the potential, welding solutions and make them Industry 3, p. 32004, Aug. 2020. applications of ML/AI in LBW for closed-loop 4.0-compatible. A bolder approach is to use a control systems are still in their infancy [6]. combined methodology, which makes use of *Pasquale Franciosa, Mikhail Sokolov, the strength of both ML/AI-based methods and Major challenges are: Tianzhu Sun, Giovanni Chianese, Darek physics-based models, and fuse them with best- Ceglarek. • ML/AI methods require large amount of in-class sensors. Although this seems daunting, data to train the models and determine with the emergence of digital technologies and predominant patterns. Large datasets are large computations available on multi-core Contact: Pasquale Franciosa rare in LBW applications, due to the cost Graphics Processor Units (GPUs), the time is [email protected] and time required to generate experimental now ripe to address the issues of in-process https://warwick.ac.uk/fac/sci/wmg samples. • Conventional ML/AI approaches can find Pasquale Franciosa is Associate Professor and Head complex non-linear patterns, but these are only reliable in the subdomain in which of laser welding applications lab at WMG, the University they have been derived and trained, and of Warwick. therefore they may be unable to accurately SEE OBSERVATIONS P27 25 ISSUE 99 WINTER 2021 THE LASER USER OBSERVATIONS
HOLLOW CORE FIBRES of micro-scale patterns, thus opening the door INTERFERENCE FOR HIGH POWER to the synergetic integration of different surface PATTERNING OF functionalities. DELIVERY IN 1 m REGION METALLIC SUBSTRATES µ Emmanuel Brousseau, Cardiff University HESHAM SAKR ET AL PETR HAUSCHWITZ
This article concerns recent developments in I would like to thank the author for a very nice This is a very interesting research on scalability hollow core fibre optics to reduce attenuation, by article, which presents the state-of-the-art of the DLIP technology and making it a viable using a “nested” structure in the fibre cladding. in laser manufacturing. From manufacturing alternative for functionalising surfaces. The The fibre attenuation values demonstrated are point of view the structure is very well made, feasibility study shows clearly the potential of indeed very impressive. Similar fibres (albeit with specifically, the precision details, 1 µm is this technology. So, this is one more piece of a higher attenuation) have been demonstrated necessary compliance the properties and the research to underpin the broader use of laser by a number of other researchers (including us at the periodicity is very well resolved with laser textured/functionalised surfaces in existing and Heriot-Watt) to deliver both high average power wavelength applied. I would be very curious to new emerging products. and high peak power laser light, enabling flexible use to adopt the technique with different laser In addition to the processing speed, another delivery of industrial ultra-short pulsed laser light source especially with wavelength below 300 “bottleneck” for the boarder use of the DLIP for precision machining applications. nm, which opens the avenue of densely packed nanostructures. technology is whether it can be employed for The main benefit of the design presented here functionalising freeform/3D surfaces and what is that it should allow this high power delivery Laser surface patterning technique has great would be the constraints if any. Anyway, with over much greater distances. Personally it is potential, it is not just for earthly applications, the increase of pulse frequencies and average hard to see the need for this in manufacturing, but it is real future for space applications too. power of the latest generation of ultrashort laser but the sub-surface rock drilling application Especially the research focused on E.coli and sources, the time for the broader use of DLIP identified by Hesham could certainly be enabled similar bacteria is finding solutions for current and multi-beam processing in combination with by this fibre. Note however that if using ultrashort problems. Last but not least, the research is very higher dynamics scan heads is coming and pulses with long lengths of this fibre, care would well organised and systematically discussed. these technologies should enable many new still required to avoid optical nonlinear effects This work would be appreciated by the general exciting applications. in the gas contained inside the fibre due to readers and the researchers in this field. self-phase modulation and Raman scattering Stefan Dimov, University of Birmingham Jan Brajer, Hilase Centre (significantly broadening the spectrum of the transmitted light), although this can be mitigated by evacuating the fibre core. Whilst lasers can be used for the surface Duncan Hand, Heriot-Watt University patterning of numerous materials, for DOWN TO THE WIRE – feature sizes in the micro- to nano-scale, Dr LASER ABLATION OF Hauchschwitz has raised a very important point in relation to the commercial uptake of MEDICAL MICRO WIRES such technologies. It has commonly been seen that a significant barrier to uptake is that of SURFACE STRUCTURES OLIVIA GILLEN & MICHAEL low throughput times. The HiLASE direct laser MITIGATE BACTERIAL O’DONNELL interference patterning (DLIP) is very interesting ADHESION as it enables the increase in productivity of This article is a well written and interesting ultra-short pulsed lasers, producing higher ANVESH GADDAM ET AL. piece, I personally appreciate the difficulties throughputs. encountered in removing so many different types The Laser-Induced Periodic Surface Structures of coating found on conductors today used in The work reported in this article by Anvesh (LIPSS) that have been demonstrated on medical, electronics and automotive electrics. Gaddam and co-authors at the University of the three different metals, within this article, From my own experience its not just about Birmingham illustrates the application of LIPSS show that this laser system also enables removing the coating you also have to consider surfaces for inhibiting bacterial growth on surface functionalisation. Metals are inherently any contaminants or oxides which can be elastomers, a typical material used in medical hydrophilic, with contact angles less than 90°, produced by the laser stripping process. devices. LIPSS topographies tend to be better and it has been shown that the HiLase DLIP known for their optical applications. At Laser Lines we have been involved with system can produce water contact angles with Stainless Steel, Invar and Tungsten of over 150° Here, the authors show that such surfaces numerous wire stripping projects, providing for each. also hold promising potential to help address applications support and the loan of laser equipment to specialist machine builders for the growing concern around hospital-acquired This type of surface functionalisation has testing suitability and practicality. infections. This is a particular application area applications in numerous industries including, but for LIPSS, which is in relative infancy and which The article describes in depth the issues not limited to, biomedical, electronics and other certainly deserves the attention of the research surrounding coating removal of single strand adhesion/surface engineering applications. This community. wires, looking to the future I can see where is highly significant as many industries are now looking to micro-scale and nano-scale surface The authors have made good strides in this laser stripping of multi core wires will become engineering for the development of products field. They not only reported a much-improved an advantage in the electronics and automotive and require the high throughput in order to meet anti-biofouling performance of the functionalised electrics sectors to aid the automation of demand. elastomer surfaces. They also demonstrated the soldering and welding. feasibility of the associated process chain as David Earl, Laser Lines David Waugh, Coventry University well as the production of such features on top 26 THE LASER USER ISSUE 99 WINTER 2021 OBSERVATIONS
LASER WELDING: due to complexity of the process and material highlights what can already be done (e.g. OCT HIGH VOLUME response to the laser energy. Pasquale presents depth measurements) and what is - or might a very good picture of the current state of this prove - harder to do (photodiode monitoring of MANUFACTURING FOR development and it is clear that more joint dissimilar welds, correlating these more ‘indirect’ E-MOBILITY effort is required between the process experts, signals reliably enough to weld quality features modelling, sensor and machine learning groups. etc.).
PASQUALE FRANCIOSA Wojciech Suder, Cranfield University It is interesting to see the article then turn to ML/ AI ± its marriage to physical models, to make ET AL. better use of this sensor data. Overall, I feel A very timely summary, rightly noting the there is a knowledge or personnel gap here, Intelligent laser processing with the aid of versatility of modern laser welding techniques between ‘welders’ and ‘data scientists’, that process algorithms and smart monitoring is now being developed for the many geometrical desperately needs bridging! So more articles urgently needed in all laser applications to utilise and materials issues in the joints needed in from AILU about results in this area would be the full benefit of high productivity, robustness automotive electrification systems. very welcome, especially as the next challenge and flexibility of lasers. The requirement for a after that will then be achieving closed-loop traditional process development by means of From a process-agnostic point of view however, control, within the few milliseconds it takes to the trial and error approach to finely tune the it would’ve been interesting to have heard the make some of these welds. process to a particular application is very costly author’s opinion about the future prospects of and hinders application of lasers. laser welding against other candidates (e.g. The future in this area certainly sounds exciting wire bonding), and some consideration of how and challenging and, from a ‘welder’s’ point of Machine learning and artificial intelligence can be these other processes might practically be used view, will require a whole new mindset to keep a way forward in resolving this issue and make alongside laser welding, e.g. for effecting repairs. up! the process more autonomous, easy to use by normal non-expert users. However, despite ‘Repair-free’ closed loop control of laser welding Chris Allen, TWI all the promises of Industry 4.0, it is still a long is of course what is most keenly desired by way to go before the real self-learning, fully manufacturers. Starting with monitoring, the autonomous laser welding is available, mainly first step towards control, the author correctly
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27 ISSUE 99 WINTER 2021 THE LASER USER FEATURE
EXCIMER LASERS ENABLE PRODUCTION OF SUPERCONDUCTING TAPES BY THE METER
The fabrication of high temperature superconducting (HTS) tape has evolved dramatically over the last decade in terms of available capacity and tape performance. To a large extent, this has been driven by the latest high-power excimer laser solutions, which have now been extended to the multi-hundred watts level. As production processes mature, the next focus becomes ramping up to higher capacity levels.
HTS-Tape Background The superior current carrying capacity of HTS- tapes at liquid nitrogen temperatures, and in the presence of high magnetic fields, make this Figure 1: Typical HTS-tape layer sequence where the micron thin rare earth barium copper oxide technology a potential game changer for many HTS-layer carries the current (layer thickness not to scale). applications still relying on copper conductors or traditional low temperature superconductors. Consequently HTS-tapes are the enabling material for many high tech market sectors, with a potential to be utilised in energy generation, power distribution, medical diagnostic instrumentation and research markets.
HTS-tapes (Figure 1) have a multilayer structure (typical tape width is 4-12 mm, typical tape height is 50 -100 µm). A key element in their structure is the superconducting YBCO thin film (typically 1-3 µm thick). This material is polycrystalline and needs to be deposited with a high degree of uniformity in terms of crystal orientation, otherwise its current carrying capability decreases exponentially.
Most uses of HTS-tapes involve coils or windings, meaning that tens to hundreds of Figure 2: Long-term pulse stability measurement of a Coherent LEAP laser operated at 300 Watt kilometers of material may be wound for even operated between two gas fills resulting in an overall average energy stability of 0.7 %, rms. relatively compact electric or magnetic devices. As an example, a 1 km long, three-phase material transfer, result in uniquely well-controlled deposition with a stable on-target fluence of superconducting high-voltage cable for an deposition of complex and polycrystalline films, typically below 1%, rms over the course of every energy grid project may use 100 to 200 km of such as superconducting yttrium barium copper gas life cycle (Figure 2). HTS-tape material. oxide (YBCO). At a typical laser discharge unit lifetime of ten Pulsed laser deposition enables high Sophisticated, large-area deposition beam billion shots, a 300 W laser can be operated with volume HTS-tape production architecture unleashes the full production only minor routine maintenance actions (such capability of powerful excimer lasers, such as automated gas fills) over the course of one Pulsed laser deposition (PLD) has emerged as the Coherent LEAP. This paves the way to five years, depending on the level of use. In at the forefront of production methods for towards cost-competitive, large-scale HTS-tape modern reel-to reel systems for HTS-tape mass fabricating HTS-tapes in batch lengths of fabrication. production, the LEAP is operated at maximum up to 1 km. This technique is practical and intensity and in three-shift operation over many cost effective, and can support the required The Coherent LEAP excimer laser, delivering years. production quality, yield and annual capacity. stabilised output power levels all the way from 80 to 300 Watts, provides the perfect Coherent LEAP excimer lasers at power levels of Pulsed laser deposition uses UV excimer laser balance between reduced capital investment 100 to 300 Watt are now used by all major PLD pulses to evaporate a sintered target material and extended maintenance cycles for high manufacturers, improving the cost-performance inside a vacuum chamber. The vaporised throughput pulsed laser deposition. LEAP thus ratio of HTS-tape tapes to a level that facilitates material subsequently condenses on the provides economical access to UV power and broader commercial market acceptance. High substrate. The density of the plasma created, precision, as demanded by every cost-sensitive temperature superconductivity in the form of as well as the kinetic energy of the ablated thin film market. PLD-made tapes is finally gaining traction. species, is orders of magnitude higher when compared to other chemical or physical vacuum High beam homogeneity, together with Contact: Petra Wallenta deposition technologies. These characteristics, unmatched pulse energy stability (typically 0.5%, [email protected] together with the stoichiometric, high yield rms), ensure accurate and reproducible thin film www.coherent.com
28 THE LASER USER ISSUE 99 WINTER 2021 ILAS 2021
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WEDNESDAY 24 MARCH THURSDAY 25 MARCH DAY 1 DAY 2
Room 1 Room 2 Room 3 Room 1 Room 2 Room 3 09:00 WELCOME TO ILAS 2021 WELCOME TO DAY 2 09:00 09:15 09:15 Plenary 1 09:30 09:30 Systems, Automation & 09:45 Drilling Surface Engineering 3 09:45 Plenary 2 Process Monitoring 10:00 10:00 10:15 10:15 Refreshment Break 10:30 10:30 Refreshment Break 10:45 10:45 11:00 11:00
11:15 Additive Manufacturing 11:15 Welding 1 Surface Texturing Discussion Panels Sources Discussion Panels 11:30 PBF 11:30 11:45 11:45 12:00 12:00 12:15 12:15 Exhibition & Lunch Break 12:30 12:30 Exhibition & Lunch Break 12:45 12:45 13:00 13:00 13:15 13:15
13:30 Ablation & 13:30 Additive Manufacturing Welding 2 Beam Delivery 13:45 Microfabrication Surface Engineering 1 Micromachining 13:45 DED 14:00 14:00 14:15 14:15 14:30 14:30 Refreshment Break 14:45 14:45 Refreshment Break 15:00 15:00 15:15 15:15 Plenary 3 15:30 Cutting Additive Manufacturing Surface Engineering 2 15:30 15:45 15:45 Plenary 4 16:00 16:00 16:15 16:15 CLOSE OF ILAS 2021 19:00-16:30 16:30 20:30 AILU Awards & Social Event Join in lively Discussion • Zoom meet-up with a glass of something chilled Panels on current hot topics • Musical entertainment Visit the Exhibitors during both lunch breaks. Enjoy live video calls. Live presentation with interactive Q&A sessions 29 ISSUE 99 WINTER 2021 THE LASER USER ILAS 2021 Bio-compatibility enhancement of a Zr-based bulk metallic glass using nanosecond laser surface texturing Brousseau, Emmanuel Cardiff University Using Machine Learning for Prediction and Optimisation in Laser Machining McDonnell, Michael University of Southampton Laser ablation surface engineering for particle accelerators Malyshev, Oleg STFC Strength of weld-joints treated by laser shock peening Shukla, Pratik Coventry University Bio-inspired non wetting surfaces by ultrafast laser processing Brajer, Jan HiLase SURFACE TEXTURING 10:45-12:15 Modelling ultrafast laser structuring/texturing of free form su rfaces Michalek, Aleksandra University of Birmingham Durability of lubricant-impregnated surfaces: the effects of l aser textured surfaces on lubricant retention under vibrations Gaddam, Anvesh University of Birmingham Laser surface texturing for industrial applications: high stati c friction and superhydrophobic surfaces Gora, Wojciech Heriot-Watt University Fast large-area multi-beam micro/nanostructuring at HiLASE Hauschwitz, Petr HiLase SURFACE ENGINEERING 1 13:15-14:30 Practical implementation of laser polishing of additively manuf actured medical implants McDonald, Mark Heriot-Watt University SURFACE ENGINEERING 2 15:00-16:15 Functionalised polycrystalline boron nitride materials through laser surface engineering Pacella, Manuela Loughborough University A study of the tactile friction behaviour between laser-texture d metallic surfaces and counterpart polyurethane materials at low sliding velocities Butler-Smith, Paul MTC Development of advanced laser processes for multiscale surface modification of functional electrodes in Liquid Chromatography-Mass Spectrometer instrumentation Ghosal, Anupam University of Manchester Hydrophobic agent adsorption dynamics of laser textured superhydrophobic metallic surfaces Macdonald, James University of Cambridge MARCH TH WEDNESDAY 24 WEDNESDAY 09:15-09:45 PLENARY 1 - Tatsuaki Furumoto, Kanazawa University 09:45-10:15 PLENARY 2 - Silke Pflueger, laser expert ADDITIVE MANUFACTURING 1 (PBF) 10:45-12:15 Understanding on microstructure and cracks of permanent magnetic material Nd-Fe- B using Laser Powder Bed Fusion Wu, Julan University of Nottingham Laser powder bed fusion additive manufacturing of functionally graded multiple metallic material components Wei, Chao University of Manchester On the use of laser-material interaction parameters to drive de sign and control of thin-wall architectures made of AlSi10Mg alloy by laser powder- bed-fusion (L-PBF) Zavala, Miguel TWI The effects of Hot Isostatic Pressing on surface integrity, microstructure and strength of hybrid MIM/PBF stainless steel components Mehmeti, Aldi University of Birmingham ADDITIVE MANUFACTURING 2 - DED 13:15-14:30 Production of super-hard cutting teeth on linear edge saw blades using Laser Directed Energy Deposition Kong, Choon Yen C4 Carbides ADDITIVE MANUFACTURING 15:00-16:30 Multi-functional representation of a novel NiTi-based compression-induced-twisting structure manufactured by selective laser melting Ma, Chenglong Nanjing University/Cardiff University Laser powder-bed fusion of aluminium based composites for enhan ced tribological performance Li, Peifeng University of Nottingham Extreme High-speed Laser Application (EHLA); a step change in high speed coating technology Barras, Josh TWI 3D printing of hybrid metal/polymer objects through an integrated multiple material additive manufacturing process Chueh, Yuan-Hui University of Manchester New approaches in additive manufacturing – Next level system te chnology and layer height control using OCT sensor Kogel-Hollacher, Markus Precitec Dilution strategies in laser cladding Koti, Daniel University of Nottingham Laser Power and Surface Thickness Analysis of Distortion Within Directed Energy Deposited In-718 Flanges Cullen, Stephen University of Huddersfield NEWAM – the next generation laser directed energy deposition process? Williams, Stewart Cranfield University CFD modelling advances in additive manufacturing Allu, Paree Flow Science Inc Process monitoring using machine learning for additive manufact uring Grünberger, Thomas plasmo WELDING 1 10:45-12:15 Temporal pulse shaping, dominant parameter in reducing welding defects during high power fiber laser welding Naeem, Mohammed Prima Power Laserdyne Fully reflective annular laser beam shaping for 1.03µm ultra-hi gh throughput laser beam welding Pallier, Gwenn Cailabs MICROFABRICATION 13:15-14:30 Maskless laser prototyping of glass microfluidic devices Wlodarczyk, Krystian Heriot-Watt University CUTTING 15:00-16:15 Advances in cutting with high power multi kilowatt fibre lasers , up to 20kW Wilford, Stan IPG Photonics Optimising the CO2 laser cutting behavior of polycarbonate Janik, Julia Synrad Optimisation of laser beam cutting with beam oscillation based on high-speed X-ray imaging Lind, Jannik University of Stuttgart New laser welding tools for titanium aerospace components Allen, Chris TWI Stress induced birefringence of glass-to-metal ultrashort pulse welded components Hann, Samuel Heriot-Watt University Ultrafast laser bonding of dissimilar materials ready for indus trial uptake Karnakis, Dimitris Oxford Lasers Laser direct writing of high quality cross-shaped terahertz mes h filter Le, Hoang University of Birmingham Laser keyhole termination regimes on varying composition of low carbon alloy steels Lai, Wai-Jun Cranfield University Investigation on the feasibility of laser riveting for dissimil ar joining applications Li, Bowei TWI
30 THE LASER USER ISSUE 99 WINTER 2021 ILAS 2021 Discussion Panel SURFACE ENGINEERING 3 09:15-10:30 TBC Liu, Zhu University of Manchester ABLATION & MICROMACHINING 13:00-14:45 Ultrashort-pulse processing with tailored laser vector fields Allegre, Olivier University of Manchester Surface engineering of polycrystalline diamond materials Ghosh, Priyanka Loughborough University Ultrafast Laser Ablation – Overview of Processing Characteristi cs Hodgson, Norman Coherent High-Power Picosecond Laser Machining of Advanced Materials Marimuthu, Sundar MTC Laser selective sintering and patterning of laser printed silve r inks for flexible electronics Arnaldo, Daniel Oxford Lasers Nanosecond Pulsed Fibre Laser Engraving of Ceramics Ahuir-Torres, Juan Liverpool John Moores University High-quality, high throughput engraving using 100 W nanosecond pulsed lasers Dondieu, Stephen Heriot-Watt University Functional microneedles : a multimodal sensory platform Dzipalski, Adrian Heriot-Watt University Fibre-tip microfabrication by ultrafast laser assisted etching Ross, Calum Heriot-Watt University MARCH TH THURSDAY 25 THURSDAY Keynote presentations are in bold print are Keynote presentations SYSTEMS, AUTOMATION & PROCESS MONITORING 09:15-10:30 Systems and Automation Jones, Tony Cyan-Tec Tailored femtosecond laser beam focused by using microscope objective lenses Li, Zhaoqing University of Manchester Trust in your laser processes with real time temperature monito ring Leach, Jim Hamamatsu Experimental investigation of accuracy, repeatability and reproducibility of multi-axis laser processing systems Karkantonis, Themistoklis University of Birmingham Scoring of tear lines for airbag application Krug, Michael Jenopik SOURCES 11:00-12:00 Tunable GHz and MHz femtosecond burst for various material proc essing Gertus, Titas Light Conversion UAB Industrial Femtosecond Lasers for High Precision Micro-Machinin g Fulford, Ben Luxinar State of the art femtosecond laser technology for the industry enabling advanced processing and higher throughput Wolters, Xavier Amplitude Systemes BEAM DELIVERY 13:00-14:45 Nanosecond UV Imaging Systems Maintain Superiority in Demanding Applications Sercel, Jeffrey J P Sercel A Hybrid Approach to Multi-physics Laser-processing for Low-volume Manufacturing Jones, Jason Hybrid Manufacturing Technologies Fully reflective one by nine beam splitter for high throughput surface decoating Pallier, Gwenn Cailabs Near Diffraction-Limited Beam Shaping for Scanner & other Long Focal Length Optical Systems for Laser Material Processing Kidd, Stephen PowerPhotonic Laser Welding in Inner Diameter (ID) of tubes having a diameter less than 145mm port Sabarikanth, S. Optilase Embedding optical sensors in additive layer manufactured metall ic components for conditional monitoring in harsh environments Michie, Benjamin Heriot-Watt University 15:15-15:45 Plenary 3 - Bill O'Neill, University of Cambridge 15:45- 16:15 Plenary 4 - Dirk Petring, Fraunhofer ILT Discussion Panel Nuburu DRILLING 09:15-10:30 Millisecond Fibre Laser Drilling of Deep Holes Marimuthu, Sundar MTC Laser direct writing of high quality cross-shaped terahertz mes h filter Le, Hoang University of Birmingham An experimental study on quasi-CW fibre laser drilling of Haste lloy- X Alloy Naeem, Mohammed Prima Power Laserdyne Pushing ultrafast laser drilling technologies to the edges Ryll, Joachim Pulsar Photonics Advanced manufacturing techniques for laser welding of automotive structural aluminium alloys Demirorer, Mete Cranfield University Comparative Evaluation of Laser Oscillation Welding applied on different functional alloys Oyelola, Olusola SPI Lasers Kilowatt Blue Laser Sources for processing solutions in eMobility Eltze, Andre Laserline GmbH Blue Lasers Poised to Enhance Automobile Fabrication Dodd, Andrew Remote Laser Welding of Die-cast Aluminium Parts for E-mobility Applications with High Frequency Beam Oscillation and Beam Shaping Franciosa, Pasquale WELDING 2 13:00-14:45 Remote laser welding of car doors with optical seam tracking Kuehnel, Matthias II-VI CFD Simulations for Laser Welding Allu, Paree Flow Science Inc
31 ISSUE 99 WINTER 2021 THE LASER USER
PRODUCT NEWS
SYSTEMS & SOURCES PRECISION & STABILITY LASER BLACK MARKING WITH LASER IN VACUUM STAINLESS AND AL LASER TUBE CUTTING The ExactMark 230 USP is Coherent's new laser black marking machine that integrates FOR BEGINNERS AND an ultrashort pulse laser. It streamlines laser EXPERTS black marking applications from prototypes through volume production. The picosecond TRUMPF has introduced two new models to laser supports corrosion-resistant black its TruLaser Tube range, respectively aimed marking of stainless steel, titanium and at those new to the technology or needing to aluminum, as well as precision marking of boost capacity and experienced users who various plastics. It is particularly well-suited for wish to ramp up production with a highly UDI marking of medical re-usables. automated machine. The first is the new TruLaser Tube 3000 fibre, a cost-effective choice even when used at low to medium capacity. The second, the TRUMPF TruLaser Tube 5000 fibre, addresses the needs of the established tube processor.
Laser welding in a vacuum enables high quality, high aspect ratio welds to be made and can give up to 4 times the penetration of atmospheric laser beam welding. Clean and consistent welds are achieved with the process and some of the undesirable aspects of electron beam welding are avoided. There are also no X-rays generated by the process. Innolas UK has launched a new Laser-in-Vacuum Processing system, ILiV420. It provides superb stability and precision and is suitable for use within any industrial environment.
Contact: Gerry Jones Contact: Ian Duckett Contact: Roy Harris [email protected] [email protected] [email protected] www.trumpf.com www.innolas.co.uk www.coherent.com
ANCILLARIES HANDHELD PORTABLE NEW, FAST LASER SLAT LASER WELDER EXACTLY POSITIONED - CLEANING IPG Photonics introduces LightWELDTM NEW AIR-BEARING STAGES handheld laser welding - it is easy to learn, simple and fast to set up and provides consistent high-quality results across a wide range of materials and thicknesses.
SS Laser Solutions introduces the Laser Slat Cleaning Machine. It is suitable for slat thicknesses of 2.5mm, 3mm and 4mm which are the common slat thicknesses in the laser market. It can be used on any laser cutting Aerotech introduces the ABRX High- machine brand and any table size. Performance Air-Bearing Stages, a new generation of air-bearing rotary tables. Various SSLS is offering AILU members a 10% Contact: Stan Wilford ABRX rotary axes are available in diameters of discount when purchasing the machine, or [email protected] 100, 150 and 250 mm. for the first 4 slat cleaning services. www.ipgphotonics.com Contact: Derrick Jepson Contact: Sinan Bilgin [email protected] [email protected] www.aerotech.com www.sslasersolutions.co.uk 32 THE LASER USER ISSUE 99 WINTER 2021
PRODUCT NEWS & FEATUREOB
COMPACT POWER METER HELPING SMEs TAKE THE FIRST STEPS INTO ADDITIVE FOR INDUSTRIAL LASERS MANUFACTURING
The Ophir Ariel from MKS Instruments is a self-contained, ultra-compact laser power meter for measuring high power industrial lasers up to 8kW. Designed for OEM and The concept of Additive Manufacturing 3. Has the part been designed for AM? end-user applications in closed and confined (otherwise known as 3D printing), whereby spaces, such as additive manufacturing, 4. Could further added value be incorporated components are manufactured in a series of metal cutting, and welding, the Ariel power in the design? layers, has been around for the best part of 30 meter is a robust, battery-powered device years. The technology has matured to deliver 5. Is 3D CAD data available for AM part that requires no water or fan cooling and is final end parts to a wide variety of industries production? small enough to fit in the palm of your hand. over the last 5 years or so. With large blue chip 6. Does the part require industry regulations or companies such as Boeing, Rolls Royce and Contact: Christian Dini acceptance standards? [email protected] Dyson investing into the technology and with www.mksinst.com the media hype surrounding Industry 4.0, it is 7. Which material and AM processes are not clear why there is still so much uncertainty suitable for the part? around the technology and why there is not a 8. What are the critical features and part wider understanding about AM and its adoption COMPACT LOADING AND specifications? within the manufacturing world. UNLOADING 9. Are further secondary processes to be Croft Additive Manufacturing Limited, FDM Digital carried out after build? With the ByTower Compact automation Solutions and the British Standards Institution solution, the productivity of a Bystronic laser have combined their knowledge, research and 10. Is the AM part a repeatable batch cutting system can be significantly increased experience alongside Innovate UK and the production run? without occupying much space. Thanks to its Additive Manufacturing Knowledge Transfer Through answering these questions an SME small footprint, the ByTower Compact opens Network (AM KTN) to create a toolbox guide to should in theory understand how their utilisation up lightly manned manufacturing for any size Additive Manufacturing. The guide specifically of AM will deliver supply chain advantages that of company. looks at 10 key questions to help Small and contribute to the Industry 4.0 ideology. The guide Medium-sized Enterprises (SMEs) when specifically talks about each point, stressing considering 3D printing as a process for their that subtractive manufacturing does not equal businesses. Additive Manufacturing and how the factors The guide aims to direct SMEs through the of using the AM process should be reviewed. consideration process of AM, rather than the Designing for Additive Manufacturing (DfAM) is actual AM manufacturing process. Firstly it one of these factors. Has the design truly been explains the 10 questions an SME should optimised to take advantage of the AM process answer before adopting the AM process. The in order to add value? guide continues expanding into each point The investment into AM can be large and with explaining elements not commonly known within SMEs in particular, the risks are high. The guide industry, and some points that are overlooked is a detailed starting point for those who wish by potential AM users when considering it as a to know more before deciding on which AM manufacturing process. process they should invest into. The toolbox indicates that the 10 questions To download the free guide please visit the to ask before adopting the AM process are as website below. follows: 1. What is the volume of AM parts required? Contact: Neil Burns Contact: Dan Thombs 2. Have other manufacturing methods been [email protected] [email protected] considered? www.croftam.co.uk/sme-firststeps/ www.bystronic.com 33 ISSUE 99 WINTER 2021 THE LASER USER A FUNNY THING
IS IT CONVENIENT TO TALK?
I don’t know whether_ you are a fan of the 1990s TV series “Father Ted”. There is a running gag about Father Ted calling his friend Father Larry Duff, which always results in Father Duff answering his phone in the most improbable and dangerous situations including skiing, driving and other situations where the distraction of a mobile ringing has disastrous results. You can find clips on YouTube if you are a fan.
Some people have a work phone and a personal phone and have the option to ignore the work phone during evenings and weekends. More commonly however, most people (like me) have a single mobile phone on which they can be contacted during downtime. One time, when I was cutting the grass on a Saturday morning, I took a call from a client who had bought a laser welder and was struggling. As a sole trader, working on a Saturday morning, he was trying to complete a challenging job with a fast turnaround. Of course I could choose to ignore such calls, but I like to pick up whenever possible (safety permitting) and find out if there is something I can do to help. In this case I think we had a 10 minute conversation about ellen-rose.co.uk off-centre loading which may or may not have solved his problem, but it was the only option available. and cramped indoors we decided to go up to talk”. I think I said something like “you will never the roof for the video and stills. I had bought a guess where I am and what I am doing” and When I started my marketing business, I wanted new microphone for my camera and came with promised to phone back later. to be able to take advantage of my photography tripod and assortment of lenses. If you have ever Looking at the results almost everything went hobby and also to be open to doing more varied been on a roof top in July in central London (in on the “cutting room floor” and the photo shoot work in the mix. As part of this I agreed to help a pre-pandemic year) it is a noisy environment. output was not really fit for the intended video out a friend who runs a fashion charity making Building work was going on nearby, sirens were producer, although I did get a nice “establishing ethical clothing, training women in India to have interrupting every minute or two, so it was clear shot” outside the store. You could call it a the skills to make clothes, school uniforms and that the ambient noise was a problem. Add wasted day, but I chose to take it as an exercise other items for the UK. She had wanted me to to this a designer with dresses made for tiny in photography and if I had to do the same again film one of her clients, a wedding dress designer models and a 2 year old recently woken, grumpy I would know what needed to be put in place. or “atelier” in London. and with tears and blotchy cheeks – and things I should have guessed that things would not be were stacked against me. What is the moral of the tale? Sometimes it is good to go outside your comfort zone and do all plain sailing and on this day there was one Taking a landscape video of wedding dresses something for nothing out of good will, and not thing after another. Firstly there was no model on a rooftop is also not ideal as two thirds of the every failure is a waste of time. for the dresses and the owner of the shop shot is not the bride. Prior planning might have was looking after her 2 year old daughter. We helped this and I was certainly in at the deep decided to go with mother and daughter in a end! At the next moment my mobile rang and an Dave MacLellan couple of dresses, and since it was a little dark AILU member and friend asked if I was “free to [email protected]
Write for THE LASER USER We Need: Contribute text & images • Business News • Press Releases • Technical Articles Contribute to the leading magazine for the laser • Observations industry. Engage with like minded experts and professionals and help promote the use of lasers. • Anecdotes We would love to hear from you, submit your • Case Studies content for the next issue of THE LASER USER. • Interviews • Tips and Tricks
To submit content send an email to [email protected] 34 THE LASER USER ISSUE 99 WINTER 2021 AILU EVENTS
FORTHCOMING AILU EVENTS
JUNE 17 2021 - ONLINE WEBINAR SEPTEMBER 29 2021 - WORKSHOP, GLASGOW LASERS DRIVE THE GREEN ECONOMY DIGITAL TECHNOLOGY IN LASER TOWARDS NET ZERO MANUFACTURING
Chair: Matthew Wasley, KTN Chair: Cliff Jolliffe, Physik Instrumente Join our webinar on the topic of laser solutions for the green This workshop will cover areas of advanced motion control, modelling, economy. Alternative forms of green energy generation like solar, AI and digital technology, highlighting the role it has to play in laser wind and wave power are enabled by laser material processing processes. Experts from industry and academia will share the latest applications and batteries are used to store energy and provide technology and applied research in this field. power for green transportation – here too there are numerous laser applications.
OCTOBER 2021 - WORKSHOP, VENUE TBA NOVEMBER 2021 - WORKSHOP, EDINBURGH
JOB SHOP ANNUAL BUSINESS MEDICAL DEVICE MANUFACTURING MEETING 2021 WITH LASERS
Chair: Mark Millar, Essex Laser Chair: Richard Carter, Heriot Watt University The annual meeting of our Job Shops covering all aspects of Held at the new Medical Device Manufacturing Centre (MDMC), this business improvement. Catch up with the latest products from workshop will allow delegates to catch up with the latest in precision machinery providers and gain insight from surveys and our processing to make medical devices. Includes a tour of the new discussion forum. If you are a laser job shop, you should come facilities at MDMC. along and meet your peers.
35 ISSUE 99 WINTER 2021 THE LASER USER EVENTS DIARY
DATE EVENT LOCATION
24-25 March 2021 ILAS 2021 Online Interactive Event 7th Industrial Laser Applications Symposium
30-31 March 2021 OCLA Virtual Symposium on Swissphotonics online Optical Coatings for Laser workshop Applications
8-11 June 2021 The 22nd International Hirosaki, Aomori, Japan Symposium on Laser Precision Microfabrication (LPM)
17 June 2021 Lasers Drive the Green Economy Online Webinar Towards Net Zero (AILU Workshop)
21-24 June 2021 Lasers in Manufacturing (LiM) International Congress 2021 Center Munich, Germany
24-26 August 2021 18th Conference on Nordic Luleå, Sweden Laser Material Processing (NOLAMP)
29 September 2021 Digital Technology in Laser Glasgow Manufacturing (AILU Workshop)
October 2021 AILU Job Shop Annual Business Venue TBA Meeting
November 2021 Medical Device Manufacturing Edinburgh with Lasers (AILU Workshop)
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