Professor Timothy Leighton FREng FRS PROFILE A TALENT FOR BURSTING BUBBLES Creatures of all sizes, from A typical research career seemed likely for would resonate with microscopic bubbles, greater heating, which could increase the Professor Timothy Leighton FREng FRS which feasibly you might have in the body. risk of damage to the foetus. The working bacteria to whales, have when he was studying undergraduate Nobody knew at the time.” Thus, began a group set out to provide answers on shaped the career of physics at the University of Cambridge. research career that applies physics in real- safety. As Professor Leighton describes the He was interested in astrophysics and world applications. process: “It was basically about coming to Professor Timothy Leighton cosmology, but felt the urge to get into Professor Leighton completed his PhD a resolution, while being wise enough to FREng FRS, but it all started the laboratory. “There was a part of me that and some follow-up work, which gave him take into account the big picture, which I wanted to feel something real between early exposure to something that became thought was engineering. in a babbling brook, where my hands,” he explains. Instead of diving increasingly important in his research. “It “It was based on rigorous maths, careful he began to research the into an undergraduate project that needed helped me to get an all-round picture of experimentation, considering the social, impressive equipment, molecular beam the different environments that people economic and ethical dimensions, and physics of sound in water. epitaxy for example, he chose an area that work in.” His research generated close coming up with a set of guidelines that I am As he explained to Michael was, as he puts it, “an acorn that could turn links with the local hospital, and he came very proud of.” The effect was widespread. into an oak tree”. His attention turned to to understand the relationship between “Since then, two billion children have been Kenward OBE, his research underwater acoustics, such as what creates clinicians and medical physicists. Professor scanned under these guidelines. changed direction when an the sound of a babbling brook. It kick-started Leighton realised that the equations at the “Over the years, the power output of a career investigating the physics of sound heart of his work would have little impact these machines was going up and up and invention to clean medical in liquids. on anyone without an understanding of up at a huge rate. I think the scientific devices brought him into Professor Leighton wanted to continue those relationships, the limitations and the community did a good job of putting in the same area when it came to a PhD environment people were in. a line in the sand and saying ‘These are the challenging world of project. Underwater acoustics might not have His first papers appeared amid debates the hazards. This is how you would antimicrobial and antibiotic been mainstream research at the Cavendish about the safety of ultrasound in foetal calculate them’.” Laboratory (Cambridge’s physics department) monitoring. “The ultrasound images back One outcome of the guidelines was resistance. at the time, but it had the limited amount in the seventies were black and white the development of onscreen displays on of equipment he needed to carry out high- and grainy. It was hard to see anything. all scanners that showed the likelihood speed photography, for example. He received If you look at today’s images, they are of various hazards to the foetus for the backing from a visiting academic that helped brilliant.” The work elicited an invitation settings in use, which allowed operators to to convince a professor so that he could from the World Federation for Ultrasound judge possible risks. “There are a couple of continue studying the physics of bubbles in in Medicine and Biology to join a working numbers shown on the screen. They don’t liquids. “It amused him as a strange offshoot,” party on the guidelines for safe foetus say ‘You can’t exceed this’. They advise the adds Professor Leighton. scanning. “I popped off to Japan, where clinician of the likelihood of a problem, The undergraduate project had focused people from many countries, industry and so the clinician would know that, if what on how gas bubbles trapped by breaking academia, and the healthcare sector got they are doing is lifesaving, disregard those waves or a waterfall make a sound. For his together and thrashed through the various numbers – they are a lower priority than PhD, Leighton reversed the process; rather hazards. I was by far the youngest there, so the medical procedure. But if the procedure than listening to what came out of a fluid, incredibly lucky and grateful to be given an is routine, you should not exceed those he set out to research what happened when unparalleled opportunity to work with the numbers.” he injected sound into it. In particular, he pioneers whose papers I had been reading,” set out to research what happens when he adds. The working party came about sound enters the womb to scan foetuses, an because there was growing interest in the PROBLEM SOLVER issue that raised safety issues as the foetus safety of ultrasound scanning, especially Professor Leighton’s work on foetal scanning is a delicate tissue. “Any mechanical system in the USA. Medics wanted ever more set the pattern for his career; he wanted that makes a sound will vibrate if you shoot detailed images but that meant pushing to have positive effects on people’s lives. sound at it close to its natural frequency,” he up the sound frequency. Scanner makers In 1992, this thinking guided his research Professor Timothy Leighton FREng FRS, Professor of Ultrasonics and Underwater Acoustics at the says. “The megahertz frequencies needed could deliver that, but higher frequencies when he moved to what is now the Faculty University of Southampton to get nice spatial resolution in images are more strongly absorbed and that means of Engineering and the Environment at 38 INGENIA INGENIA ISSUE 73 DECEMBER 2017 39 Professor Timothy Leighton FREng FRS PROFILE The natural world was also an obvious on their ‘wisdom’,” he says. “It is about subject. Professor Leighton’s research has creating meaningful dialogues and not simply Professor Leighton was inspired to invent taken in whale sounds, dolphins, fish and talking at people. You should be finding out TWIPS (twin inverted pulse sonar), and from there TWIPR (twin inverted pulse radar), with bubbles in surf. “We were the first people what is in their hearts and minds. You should colleague Paul White after watching dolphins to measure the bubble population in the be a person with a watering can, nurturing hunting with bubble nets. He also saw dolphins blowing and playing with bubble rings (whether surf – how the oceans breathe,” he says. He any seeds you find, helping them to grow, this is for recreation or education is not known) was also the first to propose how humpback giving your full attention to the person in and decided to solve the problem of how they did this while he was in a swimming pool when whales get together to produce ‘walls of front of you.” on holiday in Menorca sound’, bubble nets, to catch prey. Rather Public engagement has been important than being purely a zoologist’s problem, in Professor Leighton’s latest venture, which the University of Southampton to join the Professor Leighton says that this is an has taken him in an unexpected direction. Institute of Sound and Vibration Research. engineering issue; as is the maths that He has set himself no less a task than trying Writing papers was not enough; although dolphins use in their heads when they are to overcome the problem of antimicrobial his tally is now well over 400 publications, processing signals. He concluded what that resistance (AMR). The medical world talks studying the physics of sound underwater maths was, and so devised the world’s only in terms of an ‘antibiotic apocalypse’, the fuelled his engineer’s desire to create sonars (twin inverted pulse sonar and biased notion that sometime soon, perhaps around technologies that would solve problems. pulse summation sonar) that can detect 2050, so many bacteria will have evolved For example, collaboration with a team Professor Leighton and members of his team demonstrate StarStream to Professor Dame Sally Davies DBE FRS, Chief Medical Officer for England. An obvious mines in bubbly seawater. that can resist all known antibiotics that AMR from the National Oceanography Centre in application of this ultrasonic cleaning technology is in cleaning medical and dental instruments. Sold as StarStream, a company now has a licence to produce could be killing more people than cancer. ultrasonic cleaners for just this purpose © Mengyang Zhu Southampton produced GeoChirp 3D, the first truly three-dimensional sub-seabed PUBLIC ENGAGEMENT factory’. In reality, the factory is a cramped It protects the skin and doesn’t promote Leighton sees this as “a really important point profiler (a way of looking at what is under Research into these areas aroused media AGAINST RESISTANCE basement laboratory, filled with instruments resistance; and yet no-one I spoke to could in a world where everyone is so focused on the seabed). The technology was used to attention and fuelled Professor Leighton’s Chemists and the pharmaceuticals industry and plumbing, where Professor Leighton’s see the reason for it.” They all wanted to finding the next way of killing microbes”. image the skeleton of The Invincible, a Royal enthusiasm for public engagement. “I am see new antibiotics as the solution to AMR, small research team works on a series of emulate antibiotics and to kill the bacteria.