The World Economic Forum (WEF) has identified nanostructured materials as an enabling technology for the Fourth Industrial Revolution (Industry 4.0). One technology description of Industry 4.0 is cyber-physical infrastructure powered by a cluster of computing and communication technologies, writes Professor Saurabh Sinha.
Prof Sinha, who is the Deputy Vice-Chancellor of Research and Internationalisation at the University of Johannesburg (UJ), recently penned an opinion piece, entitled Industry 4.0 and nanostructured materials, published by eePublishers.
Industry 4.0 and nanostructured materials – Professor Saurabh Sinha
Computing performance has improved as device-level manufacturing has been miniaturised and this relationship is called Moore’s Law. A number of techniques are being presented to “extend” Moore’s law such that computing performance progress can continue to contribute to Industry 4.0. Such techniques require exploration of what is already available and typically referred to as “non-ideal properties.” It seems that the understanding and use of non-ideal properties is one such technique.
In October 2018, the Department of Science and Technology/Mintek Nanotechnology Innovation Center (NIC) and the Centre for Scientific and Industrial Research (CSIR) NIC hosted a three-day event to celebrate the ten years of the centre’s existence. I was requested to present an invited talk and was reminded of the chronological series of events in this space. In 2002, the South African Nanotechnology Initiative (SANi) was officially initiated through the DST and the CSIR played a pivotal role. Later, the CSIR NIC came about under the leadership of Prof. Suprakas Sinha Ray, also a distinguished visiting professor at the University of Johannesburg (UJ). At this three-day event, UJ was also prominently present through a number of articles. A few years ago, Prof. Suprakas became the founding chair of the IEEE Nanotechnology Council Chapter and during that time, I served as the IEEE South Africa Section Chair. The physical chemistry and chemistry connection has always been present in electronic engineering – today the connection has significantly deepened through advanced nanomaterials and nanotechnology.
In my own technical discipline in microelectronics integrated circuit (IC) design, I have witnessed transistor performance increase profoundly over the years, particularly in the last two decades. However, the challenge of system/sub-system interconnect has become even more pronounced. It is thus clear that alternatives are required and that these alternatives should be both cost-effective and scalable. These are, of course, trade-offs. The IEEE recognised that the solution to a number of IC-level trade-offs would be found through a multidisciplinary endeavour and the Nanotechnology Council (NTC) was formed. Incidentally, at a global level, the IEEE NTC was formed in February 2002 – the same year as SANi. On a side note, around 2002, our laboratory at the University of Pretoria was designing ICs with a minimum length of 0,35 µm from Austriamicrosystems AG; even by the “350 nm” (= 0.35 µm!) definition, we were too big to fit the nanoscale definition from 1-100 nm. However, there was a saying that our time would come – IC prototyping today fits within this definition.
In recent years of higher computation innovation, that time has become a reality. The industry has a great need to strive to obtain modern nano-manufacturing techniques to deposit optimal nano-thin films on nano devices. This endeavour has led to thin-film fabrication techniques that provide highly uniform, conformal, and pin-hole free quality thin films. One such technique is atomic layer deposition (ALD). Using ALD, a hybrid inorganic-organic multilayer nanostructured thin film can be fabricated. Another huge benefit of ALD is that it is capable of creating new synthesised nanostructured materials for different applications. There are however still, many unsolved fundamental issues, such as the slow growth rate, the stoichiometry, structure, and chemical quality of the deposited ultra-thin film. In addition, the sustainability of ALD nanotechnology, because of the substantial amount of toxic waste, generation of nano-particle emissions, high-energy use, etc., is a major environmental concern.
In 2017, a National Equipment Programme (NEP) grant was awarded to the UJ Principal Investigator, Prof. Tien-Chien Jen. The NEP grant acquired two complementary items of equipment for ALD study (Picosun R-200 and R-200 Advance); the first is for laboratory-scale single-wafer research, and the other is for scale-up research and industrial application for multi-wafer fabrication. This grant made it possible to fund the first ALD laboratory to be developed at UJ, making it a first for South Africa and the African continent. This technology empowers the realisation of Africa in the Industry 4.0 era, equipping the continent to develop specific nano-structures with absolute control and innovative nano-techniques. Prof. Jen and his team of versatile researchers strive to understand and study the effects of this technology by both computational and experimental investigations, to make it possible to optimise the process for next-generation technology. ALD’s ever-growing recipes for deposition make it ideal for the fabrication of new properties thin film for use in superconductors (such as TiN,TaN, NbN, etc.), catalysis development coating (Al2O3, Pt, Pd, TiO2, etc.), water purification membranes (aquaporin-based) and advanced solar cell manufacturing (CIGS, CIG, ZnO etc). These and other programmes or projects bring to practical implementation the Industry 4.0 aspiration.
Back to this three-day event, the theme was “Nanotechnology for inclusive growth: From fundamental research to industrial impact”. From an impact perspective, there are several applications of interest. Nanostructured materials (NsM) often benefit from atomic level modification and nanostructure or atomic reorganisation. For instance, a t-shirt can be designed not to smell, or dust can be eliminated from solar cells, thus improving photovoltaic efficiency, or atomic-level properties could be used for sunscreen. Of course, NsM, like most technologies, may have unintended consequences as well: if water is purified to a point where it is “too clean”, our bodies may not be used to this and water treatment would be necessary. Similarly, sunscreen development using NsM titanium dioxide (TiO2) and experimentation with people requires understanding that considers societal experimental ethics. It is, therefore, necessary for “safe and ethical usage” of NsM to be part of the initial design considerations and to be evaluated in a multidisciplinary manner during the design phase and throughout the deployment.
The workshop theme continues to be challenging, as commercialisation of nanotechnology devices remains costly and innovative thinking is therefore necessary. Such innovative thinking has already come about; for instance, we have typically sculpted by chiselling away. However, if sculpture had to be constructed by an accumulation of nanoparticles, what shape would this yield and what would this accomplish? It appears that Mother Nature has designed in this way all along. If we could replicate the top-down and bottom-up nano-manufacturing combination, we may find a new reasonable answer. Of course, our thinking may be tuned to “sculpting” in a particular way.
Artificial intelligence techniques of the machine- and deep-learning bring about an enhanced approach to the organisation of data. This analogy could also be mapped to the sculpting required for NsM development and to a bottom-up approach. Advanced computing and chemistry could therefore, in fact, converge – the development is likely to be exponentially gradual (pardon the oxymoron) as the one depends on the other. In a way, we see this with the Epic Dust Storm – the “Opportunity Rover” remains silent, un-powered, on Mars. As published in Nature Nanotechnology, the possibility for self-cleaning solar cells offers an opportunity for the future, even on Mars!
Back on earth, the cyber-physical infrastructure of 3D printing, with NsM, now has a 4D classification, where the material used for printing has the added dimension of time. The time element allows for ambience exposure variety and for material property (“programmable material”) to be similarly be adjusted.
It seems that there will be new chemistry (pardon the pun) when computing and chemistry come together for Industry 4.0 and this may be the innovative thinking required for “inclusive growth – fundamental research to industrial impact”.
· Sections relating to atomic layer deposition (ALD) have been contributed by Prof Tien-Chien Jen, Head of Department of Mechanical Engineering Science at UJ.
- The views expressed in this article are that of the author/s and do not necessarily reflect that of the University of Johannesburg.