Nigerian Journal of Technology (NIJOTECH) Vol. 32. No. 3. November 2013, pp. 379 – 385 Copyright© Faculty of Engineering, University of Nigeria, Nsukka, ISSN: 1115-8443 www.nijotech.com APPLICATION OF NANOTECHNOLOGY IN THE MANUFACTURING SECTOR: A REVIEW J. U. OOkolikolikolikoli 111, T. A. BBriggsriggs 222, I, I.I . E. M. MajorM ajorajorajor 333 1,1,1, 2,2,2, 333DEPARTMENT OF MECHANICAL ENGINEERING , UNIVERSITY OF PORT HARCOURT , PORT HARCOURT . NIGERIA E-mail addresses: 111 [email protected]; 222 [email protected]; 333 [email protected]. Abstract ThisThisThis review of the manufacturing processes in thethethe evolving field of nanotechnology describes the production of nanomaterials by the modification of conventional production techniquestechniques.. AAA number of the manufacturing techniques for nanonanomaterialsmaterials production andandand ttthethe challenges in the adaptation of the processes to enable nano production are highlightedhighlighted.... Examples of practical applications of nanonano----structures,structures, materials and components are given. TTTheThe challenges and risks their applications pose to the wider society are discussed. Suggestions are made on how the social and ethical implications of nanotechnology can best be addressed. A pA propp roproproposososositionition on the way forward for nano production and thethethe integration of thetheiriririr products in the society isisis also discussed. The challenges andandand prospectprospectssss in nanonano----manufacturingmanufacturing areareare presented. KeywordKeywordssss::: nanotechnology, nano-materials, nano-manufacturing, nano-production, production engineering 111.1 IIIntroductionIntroduction The main methods for the production of Global economic pressures as a catalyst for energy nanoparticles can be grouped into three [4,5]: (i) conservation and optimal utilization of resources physicochemical methods e.g. the creation of continuously challenge the engineering profession, nanoparticles using preformed polymers and particularly production engineering, to seek for inducing their precipitation by emulsification– increasingly sophisticated devices and structures solvent evaporation, diffusion or reverse salting- with novel properties, and products of decreasing out, (ii) in situ chemical synthesis methods of component sizes thereby fulfilling the objective of macromolecules, giving rise for instance to achieving less material usages and hence less polymerization or interfacial poly-condensation energy consumption. Nano materials production is reactions [6], (iii) mechanical methods e.g. use of a response to this global trend. The achievement of high-energy devices like high pressure that goal through nano materials manufacture can homogenizers, sonifiers [4], or high-energy wet only be found in the development of state of the art mills [7]. The focus here is primarily on the manufacturing techniques that drive nano-size mechanical method because it has provided cost- production. Nanoscale manufacturing refers to the effective techniques that have made their way into production of structures, materials and components several scientific areas, such as biomedicine, with at least one lateral dimension between 1 nm filtration, electronics, sensors, catalysis and and 100 nm including surface and subsurface composites [8,9], and fabrication involving patterns, 3D nano structures, nano-wires, nano- materials like metals [10,11,12], non-metals like tubes and nano-particles [1]. Potential benefits semiconductors [10,13], magnetic multilayered result from miniaturization (e.g., sensors) and from nanowires [14], glasses, nanotubules [10]. the unique properties of the materials (e.g., high This paper reviews advances in the development of strength). A logical step in the drive to meet the nano-manufacturing technologies in order to demand for product miniaturization and nano- highlight the state of the art and challenges. Their material and structures enabled novel functionality industrial applications and scientific/ technological is to achieve the desired nano precision and challenges are also discussed. resolution through the development and wide implementation of nanofabrication technologies 2.0 Methods of nanonanonanomatenano matematerialsrials production [2,3]. Nanotechnology offers the possibility of The following methods are used for the production introducing technologies that are more efficient and of nanomaterials: environmentally sound than those used today. Nigerian Journal of Technology Vol. 32, No. 3, November 2013 379 AAAPPLICATION OF NNNANOTECHNOLOGY IN THE MMMANUFACTURING SSSECTOR ::: AAA RRREVIEW ,,, J. U. Okoli , et al 2.12.12.1 Electrospinning technology for nano fibre configuration [21]. Spray drying comprises production atomization of feed into spray, spray-air contact, Nano fibres production has been achieved by use of drying of spray and separation of dried product the electrospinning technology to produce three from the drying air [20]. dimensional, ultra-fine fibres with diameters in the The Nano Spray Dryer B-90 (Buchi company) range of a few nanometers (more typically 100 nm (Figure 1) utilizes a vibrating mesh technology for to 1 micron) and lengths up to kilometers. These fine droplets generation. It consists of a piezo- nano fibres present unique properties such as electric driven crystal spray head (Figure 2) which extraordinarily high surface area per unit mass, is incorporated with a spray cap that contains a thin very high porosity, tunable pore size, tunable perforated membrane (spray mesh) having an surface properties, layer thinness, high array of precise micron-sized holes. Driving the permeability, low basic weight, ability to retain piezo-electric actuator at ultra-sonic frequency electrostatic charges and cost effectiveness among causes the mesh to vibrate up and down thereby of others[15]. injecting millions of precisely sized droplets Being a continuous process, electro spinning through the holes generating aerosols [21]. This disposes itself to high volume production of nano equipment operates on a laminar fluid flow fibres. The orientation of fibres which is crucial for principle, in which the laminar flow is generated by different applications of nano fibres is obtained air passing through compact porous metal foam through set-ups during manufacture. Rotating that is conducive for optimal energy input and has collection devices are the most common set-ups. short heating up rates. Laminar flow lends itself to One technique is dry rotary electro spinning which gentle heating which makes the system ideal for involves the organizational alignment of electro heat sensitive biopharmaceutical products. Its spun nano-fibres in planer assembly [16]. Another vertical spray dryer configuration facilitates direct technique is a scanned electro spinning nano fibre and straight down collection of particles into the deposition system. This method achieves uniform collector, which helps to minimize particle fibre deposition and produces self-assembled adherence to the side of the walls of the glass composite fibres of micro- and nano particles chamber, thereby allowing for much higher aligned in a polymetric fibre. collection yields. One primary advantage of electro spinning is that it The application of nano-particles which is favoured can be customized to produce nano fibres to meet over micro-particles in drug delivery due to their the requirements of specific applications. Carbon small size and higher specific area which favourably and ceramic nano fibres made of polymeric results in much improved distribution rates and precursors further expand the list of possible uses bioavailability [22] has driven their inclusion in of electro spinning nano fibres [17]. This production many formulations by pharmaceutical companies process has impacted several scientific areas such and generated interest in the development of as biomedicine, filtration, electronics, sensors, matching production techniques. catalysis and composites [9, 18,]. Electro spinning has proven to be a very simple and 2.3 Template synthesissynthesis---- membrane based technology versatile method of producing and handling a wide for generation of nano/micro materials range of materials that can be spun. This top down The basic principles of templates synthesis is micro/ nano production method is of relatively low similar to that of producing components through cost compared to that of most bottom-up methods; the use of replication for example like making ice it is also environmentally friendly because it candies out of moulds [23]. This technique involves consumes only a small amount of electrical energy the deposition of materials within the pores of the [19]. membranes by either electrochemical or chemical (electroless) reduction of the appropriate metal ion. 2.2 Nano particles by spraying The structures produced are either homogeneous Spraying drying has been found to be a suitable or heterogeneous. Several researchers have used method that offers the advantage of drying and this technique and its refinements in the fabrication particle formation in a single step continuous and of thin wires as small as 20 nm using mica with scalable process with general engineering etched pores as templates for the growth of such possibilities [20]. Typically various particle elements of the microstructures [24, 25, 26]. properties such as particle size, bulk density and flow properties can be easily tuned through simple manipulation of process parameters