Symposia
"Reunite, Invigorate and Create an Inspiring Future"

Ionic liquids have received much attention as tribological additives and lubricants, due to their tuneability but also due to the possibility of controlling the surface composition using an applied field. This electrically addressable boundary lubrication depends on the intricacies of the interfacial ordering of ionic materials, which is dependent on self assembly and coulombic interactions. Experimentally these films are very inaccessible and require the development of new methodologies to probe them.

The lecture will discuss the principles of lubrication by liquid salts and, what approaches can be deployed to quantify the relationship between the observed tribology and nanotribology , and the changing ionic compositions under electric fields.

A surface chemist turned nanotribologist from Australia who has lived and worked in Sweden for 25 years. A PhD (1992) from the Australian National University in surface forces, postdocs at Lehigh University and The Institute for Surface Chemistry Stockholm followed by 4 years lecturing at the University of Sydney. At KTH The Royal Institute of Technology in Stockholm since 1998, professor since 2005. The surface has always been the focus, with interfacial self-assembly as an early theme. Interdisciplinary connections include (nano)tribology and psychophysics, with applications ranging from electroresponsive interfacial behaviour, through biolubrication, pharma and cosmetics.

The classical hydrodynamic lubrication equation, known as Reynolds equation, and its various modified forms, were derived on the basic assumption of fluid flow through a narrow gap between moving parts under steady conditions, and thus are not applicable to situations of non-steady work conditions. Taking three dynamic effects, acceleration/deceleration of the moving part of conjunctions, non-steady variation of the boundaries of lubricated zone and the time-dependent rheology of the fluid, into account, an expanded Reynolds equation is derived. It is pointed out that the hydrodynamic lubrication problem under non-steady conditions is no longer defined solely by the lubrication equation, the complementary equations governing the dynamics of the conjunction parts, fluid flow outside the lubricated zones as well as the rate-, state- and temperature-dependent rheology model of fluids are required to solve the problem. The new equation has been applied to analyze the variations of fluid film thickness of a plain bearing with time during acceleration and deceleration periods, and compared with the experiment results of a test rig in literature.

Dr. Yonggang Meng is a Professor in Mechanical Engineering at the State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing, China. He received his MS and PhD degrees from Kumamoto University, Japan, in 1986 and 1989 respectively. His current research interests cover modeling of friction, wear and lubrication in macro/micro-tribosystems and its applications to tribological design of machine elements.

We still live in the age dominated by car and mass production of goods which started at the beginning of the 20^th century. New technologies were developed then, promising an easy exit from the looming stagnation. New machinery built required thorough understanding of the phenomena taking place at the interfaces of moving surfaces. Furthermore, we needed to control these interactions. Initial practical ideas of applying oil to reduce friction and wear had been replaced by more deliberate actions based on fundamental knowledge gained from theoretical studies of lubrication regimes. The tribology was born. Gradually we developed scientific foundations essential in the design of bearings, clutches, gears, brakes, etc., in formulating novel lubricants, in manufacturing of wear resistant materials and surface treatments. We even developed replacements for the knee and hip joints. Now, we are at the threshold of significant shift that would be dictated by a combination of numerical revolution, new energy producing technologies and novel ways of goods production. These changes are rapid and within the next decade we could be living in the new era, and as always tribology will be there to assist us.

In this presentation, the importance of tribology, from the early times until today, is briefly outlined. The problems that we currently face with a possible paradigm change and the role tribology would play in the rapidly evolving future are discussed.

Emeritus Professor Stachowiak has been working in tribology for over 40 years. He is the Editor of Tribology and Practice book series published by John Wiley and member of the Editorial Boards of several tribological and bio-medical journals. He has published extensively and wrote/contributed to several books. He is the leading author of the books ‘Engineering Tribology’, 'Experimental Methods in Tribology', published by Elsevier, and an editor of the book ‘Wear – Materials, Mechanisms and Practice’, published by John Wiley and Sons, Ltd. In 2012 he was awarded the title of Doctor Honoris Causa from the Ecole Centrale de Lyon, France and in 2014, he was awarded Tribology Gold Medal, the world's highest award in tribology in recognition of his outstanding contributions to tribology. He still works on solutions to tribological problems.

With stringent environmental regulations and tougher economic reasons, tribological components like rolling bearings and gears are constantly under scrutiny when it comes to energy efficiency and reliability. This has driven engineers towards the constant search of new materials, new designs and optimal performance of components, particularly in tribological surfaces. All this has stimulated research with the aim to develop engineering knowledge to better select or better design mechanical components like gears and rolling bearings (often the most loaded surfaces in a machine). This talk will summarize our efforts in tribological modelling aspects leading to the prediction of different surface failure modes and eventually the life of the whole machine element. Aspects related to surface distress, wear, fatigue and the competition of these phenomena will be discussed.

Principal Scientist SKF Research and Technology Development, The Netherlands, Chair Professor at LaMCoS, INSA de Lyon, France. Visiting Professor at Imperial College London.

PhD in Tribology from the University of Cambridge, U.K., holder of “Habilitation à Diriger des Recherches (INSA-Lyon)”, 10 years lecturer in university and 23 years of experience in rolling bearings. Author of more than 70 scientific papers and several book chapters. Associated Editor of Tribology Transactions and IMechE Part J.
Scientific interests are: Modelling of Bearing life, friction, lubrication and surface life.

Two dimensional (2D) nanomaterials have shown great potential as lubricant additives. In this presentation, discussion focuses on nanostructured (2D) α-zirconium phosphate (α-ZrP) and its effects on lubrication. Nanoplatelets were added in both non-aqueous and aqueous base fluids. Tribological characterization showed the unexpected reduction in friction to 60% and 90%, respectively in mineral oil and water. There are two possibilities for such reduction: intermolecular interaction and modification of viscosity. Details will be further discussed regarding the structure of nanoparticles and its influence on fluidic behavior.

Dr. Hong Liang is the Oscar S. Wyatt Jr. Professor at J. Mike Walker ’66 Department of Mechanical Engineering, Texas A&M University. She is currently the vice president of the Society of Tribologists and Lubrication Engineers (STLE) and will be the president of STLE in May 2023 for a year. Prof. Liang research lies in the chemical-mechanical polishing (CMP), nano- and bio-materials, surfaces, and interfaces. She is currently focusing on nanolubricants, design and fabrication of wear resistant materials, and energy storage devices. Professor Liang is an editor for Tribology International and has been on board of a few other journals. She is a fellow of the American Society of Mechanical Engineers (ASME) and a Fellow of STLE. In her service to STLE, she was a member of the Board of Directors for STLE from 2007 to 2013. She served on the Annual Meeting Program Committee and was the program chair in 2007. She was the ASME Swanson Fellow and served as assistant director for research partnerships for the Office of Advanced Manufacturing at National Institute of Standards and Technology (2018-2019).

Solid lubricants such as graphite, multiwall carbon nanotubes and PTFE can be used in low-pressure applications. Until now, it was unclear whether their lubricity is also sufficient for high contact pressures, for example in rolling bearings. This lecture demonstrates that high pressure solid lubrication is a viable option when liquid lubricants fail. Furthermore, it provides deep insights into the mechanism underlying solid lubrication by PTFE, graphite and multiwall carbon nanotubes. Classical and quantum molecular dynamics simulations along with experimental tribometry and analytics reveal the crucial role of structural transformations in the solid lubricants and their impact on lubricity. While PTFE chains align during pressurized sliding, graphite and multiwall carbon nanotubes form new amorphous carbon tribomaterials with intermediate range order. For the latter two lubricants, water plays a crucial role in passivation of the observed turbostratic carbon tribolayers.

Prof. Dr. Michael Moseler is a German Physicist and Materials Scientist with a strong focus on atomistic modelling of friction and wear as well as nanomaterials. He holds a Professorship for “Simulation of Functional Nanosystems” at the Physics Department of Freiburg University and he is leader of the applied research group “Multiscale modeling and Tribosimulations” at the Fraunhofer Institute for Mechanics of Materials IWM. His research activities cover classical and quantum molecular dynamics simulations of tribo-induced phase transitions, rheology and reactivity of lubricants in narrow gaps as well as fundamental mechanisms underlying superlubricity. In 2022 Moseler received the prestigious Stifterverband Science Prize for his “Virtual Material Probe for Tribological Contacts” (see https://youtu.be/c75_Z7WdHms).

With the recent arrival of exascale supercomputers, computing landscape is evolving rapidly. While quantum computers have outperformed the fastest supercomputers for certain problems, artificial intelligence (AI) is transforming every aspect of our life. To utilize these new advances for materials simulations, we are developing an AI and quantum-computing enabled exascale materials simulator (AIQ-XMaS). I will describe the application of the software to quantum, reactive and neural-network simulations of interfacial phenomena, including: (1) picosecond optical, electrical and mechanical control of symmetric breaking in topological skyrmion and skyrmionium at ferroelectric/paraelectric interfaces for emerging ultralow-power polar topotronics; and (2) self-assembly of layered material metastructures on strained substrate for scalable and robust manufacturing of quantum emitters for future quantum information science and technology. This research was supported by NSF Future Manufacturing Program, Award 2036359 and NSF Cybertraining Program, Award 2118061. Simulations were performed at Argonne Leadership Computing Facility under DOE INCITE and Aurora Early Science programs and at the Center for Advanced Research Computing of the University of Southern California.

Aiichiro Nakano is a professor of Computer Science with joint appointments in Physics & Astronomy, Quantitative & Computational Biology, and Collaboratory for Advanced Computing and Simulations at the University of Southern California. He received a Ph.D. in physics from the University of Tokyo, Japan. He has authored 478 refereed articles in the areas of scalable scientific algorithms, high-end parallel supercomputing, scientific visualization and informatics, and computational materials science. He is a Fellow of the American Physical Society.

Aiichiro Nakano is a professor of Computer Science with joint appointments in Physics & Astronomy, Quantitative & Computational Biology, and Collaboratory for Advanced Computing and Simulations at the University of Southern California. He received a Ph.D. in physics from the University of Tokyo, Japan. He has authored 478 refereed articles in the areas of scalable scientific algorithms, high-end parallel supercomputing, scientific visualization and informatics, and computational materials science. He is a Fellow of the American Physical Society.

Liquid Superlubricity (LSL) defines the regime when a liquid lubricant is present in the contact and that the dynamic friction coefficient is below 0.01 under boundary conditions. Under HL and full EHL, such a regime is attainable with traditional oils and is well explained by viscosity-based theories. Under boundary conditions, the situation is much more challenging and both friction materials and lubricants must be changed in order to reach LSL. Here, we present several superlubricious technologies leading to green LSL and low wear under severe boundary conditions. We used ta-C- coated steel and commercially available silicon-based hot-pressed micro-crystalline ceramics substrates (SiC and Si3N4). For selected green lubricants, polyols (glycerol), unsaturated fatty acids and hypericin additive are used. The mechanisms for SLS are threefold and are related to complex tribochemical reactions: extended very thin film EHL by surface polishing, friction-induced aromatization (graphene, carbon nitride), hydroxyl termination and corresponding hybrid combinations of these latter, this depending on contact severity (lambda ratios). Computer simulation is very useful to explain how tribochemical reactions can lead to LSL. This technology could be very useful in many fields including EV, hydraulic fluids and biological applications.

Emeritus Professor Jean Michel Martin is a French Chemist with a specialty on surface analytical characterization and tribochemistry. He belongs to the Laboratory of Tribology and System Dynamics at Ecole Centrale de Lyon, a French “Grande Ecole” of Lyon university. His research activities have been entirely devoted to tribology with more than 50 years of extensive experience in fundamental and applied research in tribology of thin films, gas phase lubrication, diamond-like coatings, boundary lubrication, anti-wear and extreme-pressure additives, friction modifiers, surface chemical analysis and more recently liquid superlubricity. In 2019, he received the Tribochemistry Award from the JAST in Japan and was awarded Tribology Gold Medal, the world’s highest award in tribology in recognition of his outstanding contributions to tribochemistry. He still works on applications of superlubricity in the real world.

Concerted efforts have been made to advance the bio-tribological performances of UHMWPE for hip and knee implant applications. At the same time, several other potential solutions have also been researched. For example, PEEK composites and hydrogels are promising alternatives, however, much research still needs to be carried out to find acceptable performances. The present author and co-workers have tested epoxy-based composites where UHMWPE particles were added as property enhancer. In multi-directional pin-on-disc test the new composites have performed somewhat better than a typical UHMWPE sample. This shows some potential for the development of epoxy-uhmwpe composite for future bio-tribological research. In this talk, we will present some of earlier experimental data on the wear results of the new composites.

Dr. Sujeet K Sinha received his Master’s degree from the Indian Institute of Science, Bangalore (1991) and PhD from Imperial College London (1994). Presently, he is working as a professor in the Department of Mechanical Engineering, Indian Institute of Technology Delhi. He has worked extensively in the fields of nanotribology, polymer tribology and tribological applications of polymer composites as bearing materials for general engineering and for bio-medical applications. He contributed to the use of polymeric soft coatings for hard substrates as a durable tribological solution. Presently he is working on innovating new polymeric material concepts for hip and knee implant applications. He has co-edited the first book on Polymer Tribology (2009) and edited a Handbook on Polymer Tribology (2018). He has published more than 140 journal papers and edited/co-edited several research books and special issues.

Before Dr. Sinha’s present position, he was a Guest Researcher at the National Institute of Standards and Technology (NIST), Gaithersburg, USA (2000), a post-doctoral researcher at the Advanced Institute of Science and Technology (AIST), Tsukuba, Japan (2001), and a teaching faculty in the Department of Mechanical Engineering of the National University of Singapore (2001-2012).

Although great progress has been made demonstrating superlubricity utilizing various two-dimensional (2D) materials as a solid lubricant, in various environments and at moderate to high contact pressures, the sustained, long-term reliability of these solid lubricants in more complex tribological conditions is yet to be established to consider them as a potential candidate for replacing oil-based lubricants. In this study, we show the demonstration of a fully dry solid lubricant showing superlubricity in rough steel against steel sliding-rolling contacts at high contact pressures (1GPa). We utilize MoS2+Graphene Oxide as a solid lubricant to produce ultra-low friction of 0.005 under rolling-sliding conditions for up to 200 hours (70 km) of uninterrupted rolling-sliding. This was observed to result from complex physico-chemical and physico-mechanical phenomena occurring in situ in the tribolayer. I’ll discuss the mechanism of formation of tribolayer that is playing a key role in the friction reduction. This demonstration paves the way for further development and realization of oil-free superlubricity in various real-world applications and helps toward the decarbonization goal in the lubrication industry.

Dr. Anirudha Sumant is a Group Leader of the Nanofabrication and Devices Group and Materials Scientist at the Center for Nanoscale Materials, Argonne National Laboratory, and leading the research on nanocarbon materials including CVD-diamond, carbon nanotube, graphene as well as other 2D materials. His work on demonstrating superlubricity (near-zero friction) at an engineering scale opened a new era in solid lubrication technology. He has more than 25 years of research experience in the synthesis, characterization, and development of various applications based on nanocarbon materials including CVD-diamond and graphene. His main research interests include electronic, mechanical, and tribological properties of carbon-based materials and other 2D materials as well as surface chemistry, and micro-nano fabrication. He is the author and co-author of more than 150 peer-reviewed journal/proceedings publications, 2 book chapters, and has 36 granted patents. The list of his awards includes four R&D 100 awards, NASA Tech Brief Magazine Award, three TechConnect National Innovation Awards, the Pinnacle of Education Award, and the Excellence in Commercialization Award. He is a member of MRS, STLE, and AVS and is currently an editorial advisory board member for Applied Physics Letters and the specialty Chief Editor of the journal Frontiers in Carbon.

Argonne web page: https://www.anl.gov/profile/anirudha-v-sumant
Research highlights and portfolio: https://www.anl.gov/novel-nanocarbon-materials
LinkedIn profile: http://www.linkedin.com/in/anisumant
Google Scholar: http://scholar.google.com/citations?user=4dDO-10AAAAJ&hl=en&oi=ao

Stimuli-responsive polymers undergo changes in their structure in response to external stimuli such as pH and temperature, similarly to biological molecules and systems. Their fascinating properties suggest many future opportunities in designing sensors, drug delivery, and cell culture systems. As bioinspired materials, we prepared biomolecularly stimuli-responsive gels that exhibit swelling/shrinking behaviors or sol-gel transition in response to a target biomolecule such as an antibody and tumor marker. Stimuli-responsive gels with molecular binding sites like proteins regulated drug release by conformational changes in response to a change in pH and temperature. Interestingly, temperature-responsive polymer networks enabled us to harvest liquid water from the air. Recently we also proposed a universal method to easily design tough gels using entanglements of polymer chains. Liquid crystalline polymers that have highly oriented and dynamic structures similar to those of biological membranes were also used for fabricating bioinspired materials and systems. This paper highlights our recent studies on various bioinspired materials designed using dynamic structures and their applications.

Takashi Miyata received his Master's degree from Kobe University in 1989. He started his academic career as Assistant Professor at Kansai University in 1991. Then he received his Ph.D. degree from Kobe University in 1994. He was promoted to Associate Professor in 1999 and Full Professor in 2008 at Kansai University. He also conducted research as a Visiting Scientist at Stanford University (1997) and as a PRESTO Researcher of Japan Science and Technology Agency (JST) (2002–2010). His research group has designed various smart soft materials such as hydrogels, membranes, films, and particles for biomedical and environmental applications. He received several scientific awards, for example, SPSJ Wiley Award (2008), The Award of the Society of Polymer Science, Japan (2020), The Award of The Society of Fiber Science and Technology, Japan (2020), The Award of The Adhesion Society of Japan (2022) and so on.

Accidents, diseases and malformation by birth, cause damage in natural synovial joints, which demand Total Joint Replacement (TJR) surgery as treatment. Modern TJR as we know it now was first developed in the 1960s. Since then, because of the improved components´ design and surgical methods the implant's service life has been substantially prolonged. Despite an increasingly active and longer-living population, as well as a trend toward joint replacement at a young age, modern improved implant technology has enabled TJR surgery to reach a success rate of 95%. Nonetheless, wear debris, is and has been the major cause of implant failure and need for revision surgery. Therefore, greater innovation is required in terms of design, material development, and processing techniques. Additive manufacturing/3D printing is in continuous rise due to its versatility, customizability to fabricate complex structures and geometries, economical and rapid manufacturing process. Polymers particularly has been the center of attraction of 3D printing due to the ease of production and availability. In this presentation, the benefits, and weaknesses of 3D printing versus the conventional manufacturing with focus of strength and weakness on tribological and mechanical aspects for orthopedic applications will be discussed.

Professor Emami has a PhD within Polymeric Composite Materials. She is leader for biotribology and polymer composite tribology research areas at Division of Machine element, Luleå University of Technology, Sweden. Her research area covers development and processing of multi-scale and functional polymer composites for load bearing applications. Prof. Emami research projects covers processing of functional reinforced thermoplastic composites within tribological applications and surface functionalization of graphene/2D materials and other nanomaterials. Over the last five years she has been invited speaker/keynote speaker in more than  20  international conferences. Her publications can be found in journals such as Scientific reports, Colloid and Interface Science, Materials & Design, Journal of Sustainable Materials and Technologies, Composite part B, Journal of Biomedical Materials Research. Part B, Journal of Hazardous Materials, Wear, Tribology International and more. Prof. Emami is PI in two MSCA-ITN.

Improved lubrication continues to have a role to play in the reduction of energy losses in vehicles, machinery, and power-generation equipment. Some of the effective friction modifiers from the last century, many of which were developed for internal combustion engines, rely on elevated temperatures in order to function effectively, and alternatives for sliding systems operating at lower temperatures need to be developed. Polymer brushes—already well known as lubricious surfaces in nature and in certain biomedical devices—also show promise in heavier duty machine environments. The challenge is to develop a self-healing system where brush-forming molecules can simply be present in the lubricant and replace molecules that have been removed by wear. Some approaches towards this goal will be discussed.

Nicholas Spencer was born in the UK and educated in Cambridge before going to the USA for a postdoc in UC Berkeley, followed by a decade in the US chemical industry. For the last thirty years he has been Professor of Surface Science and Technology at ETH Zurich, working on topics ranging from hip implants to lubricant additives, and is particularly known for his work on polymer-brush lubrication. He is Editor-in-Chief of Tribology Letters and the winner of the 2018 Tribology Gold Medal and the 2022 STLE International Award. Since January 2023 he has been President of the International Tribology Council.

Lubricants are originally sustainable materials, and they contribute to lessening energy loss by reducing friction in machines and preventing wearing of materials to the minimum. In this time, we will explain how lubricants can contribute to a sustainable society from aspects such as energy and fuel conservation and biodegradation. In addition, we will introduce the suitable type of lubricants that is suitable for nature-friendly technologies such as electric cars and wind power generators. Lastly, we will discuss about the current roles and the future of sustainable lubricants.

Mr. Fumiaki Takagi received MS degrees in Applied Chemistry from Chiba University, Japan. In 1993, he joined Idemitsu Kosan Co.,Ltd as organic synthesis researcher. Since 1999, he has researched and developed lubricants. Now is General Manager of Lubricants Research Laboratory in Idemitsu Kosan Co.,Ltd. His research interests include friction reduction, oxidation reaction of oil, interfacial chemistry, surface phenomena, electrochemistry, metal processing and metal working oil.