Keynote Speakers

Dr. Ali Erdemir

Texas A&M University, Department of Mechanical Engineering
College Station, TX 77843

Frontier of Catalyst-drive Tribochemistry: Implications for Friction and Wear
Monday, November 9, 2020 at 9:00 am CT

Abstract
At present, many types of tribological coatings (such as diamondlike carbon) and lubricating oils are used to combat friction and wear-related problems in moving mechanical systems. However, under the increasingly more stringent operating conditions, these coatings and lubricants are falling short in meeting durability and efficiency expectations especially when ultra-low viscosity oils with reduced anti-wear and -friction additives are used. We have developed a new class of nano-composite coatings consisting of catalytically active hard and soft phases (i.e., VN, NbN, WN, MoN, HfN, and Ni, Cu, Co, Ag, etc.) which provide excellent catalytic responsiveness to the hydrocarbon molecules of base oils. Specifically, when tested in neat or minimally additized base oils, these catalytic coatings fragment long-chain hydrocarbon molecules of oils to produce a carbon-rich boundary film whose structural chemistry is similar to those of DLC which has been well-known for its favorable friction and wear properties. Furthermore, we have demonstrated that if present in the operating environments, these coatings can also extract DLC films on rubbing surfaces from hydrocarbon gases such as, methane or natural gas. With the use of catalyst-enabled metal-organic additives, we could also extract DLC boundary films from base oils without the use of a catalytic coating. Overall, comprehensive tribological studies have confirmed that these nanocomposite coatings could serve as next generation materials for a wide range of tribological applications by increasing component durability, energy efficiency, and environmental compatibility.

Biography 
Dr. ALI ERDEMIR is a TEES Eminent Professor in the Mechanical Engineering Department of Texas A&M University, College Station, Texas. Formerly, he was an Argonne Distinguished Fellow and Senior Scientist at Argonne National Laboratory. In recognition of his research accomplishments, Dr. Erdemir has received numerous coveted awards (including STLE’s International Award, ASME’s Mayo D. Hersey Award, the University of Chicago’s Medal of Distinguished Performance, six R&D 100 Awards, two Al Sonntag Awards and an Edmond E. Bisson Award from STLE) and such honors as being elected to the National Academy of Engineering, the presidency of the International Tribology Council and STLE. He is also a Fellow of AAAS, ASME, STLE, AVS, and ASM-International. He has authored/co-authored more than 300 research articles and 18 book/handbook chapters, co-edited four books, presented more than 180 invited/keynote/plenary talks, and holds 28 U.S. patents. His current research is directed toward the development of novel tribological technologies for a broad range of applications in manufacturing, transportation, and other energy conversion and utilization systems.

Dr. Carmel Majidi

Clarence H. Adamson Professor of Mechanical Engineering 
Carnegie Mellon University, Pittsburgh, PA 15213
cmajidi@andrew.cmu.edu • 412.268.2492 • http://sml.me.cmu.edu 

Challenges at the Interface in Soft, Stretchable Electronics
Monday, November 9, 2020 at 1:00 pm CT

Abstract

Despite remarkable advances in the miniaturization of electronics and electromechanical systems, existing computing and robotic systems are still too bulky for robust, physical human-machine interaction. This is due to the large stiffness mismatch between soft biological tissue and the rigid materials used for circuits, actuators, and hardware packaging.  Recently, this has been addressed with exciting new classes of hybrid material systems that combine rigid microelectronics with soft-matter sensors, circuits, and actuators that match the compliance and elasticity of natural skin, nervous tissue, and muscle.  These highly integrated technologies represent the building blocks of soft machines and electronics that are not only biocompatible, but can also be utilized in soft bio-inspired robots that exhibit the rich versatility of natural organisms.  However, further progress is currently impaired by challenges that arise at the interface between soft functional materials and embedded microelectronic components. 

In this talk, I will review recent efforts in soft materials integration, with special attention on the challenges that arise when attempting to create robust interfaces between mechanically disparate materials.  This includes issues with bonding an elastomer substrate to the rigid housing of a miniaturized device and robust adhesion or wetting of soft conductive wiring to the pins of an IC chip.  I will also discuss tradeoffs and emerging solutions in thermal conductivity, interfacial contact resistance, and heat management in applications of soft materials to heat generating machines and electronics.In closing, I will highlight open challenges and opportunities for future advancements at the intersection of elastically deformable machines and electronics, soft and rigid materials integration, and interfacial science.

Biography

Carmel Majidi is the Clarence H. Adamson Professor of Mechanical Engineering at Carnegie Mellon University, where he leads the Soft Machines Lab.  His lab is dedicated to the discovery of novel material architectures that allow machines and electronics to be soft, elastically deformable, and biomechanically compatible.  Currently, his research is focused on fluid-filled elastomers that exhibit unique combinations of mechanical, electrical, and thermal properties and can function as “artificial” skin, nervous tissue, and muscle for soft robotics and wearables.  Carmel has received grants from industry and federal agencies along with early career awards from DARPA, ONR, AFOSR, and NASA to explore challenges in soft-matter engineering and robotics.  Prior to arriving at CMU, Prof. Majidi had postdoctoral appointments at Harvard and Princeton Universities and received his PhD in Electrical Engineering at UC Berkeley.

Dr. Rosa Espinosa-Marzal

Associate Professor, University of Illinois at Urbana-Champaign
Urbana, IL 61801
 
Modulating slip, adhesion and friction of graphene via substrate-induced doping
Tuesday, November 10, 2020, 9:00 am CT

Abstract

Graphene is seen as a potential coating material to control friction at interfaces due to its crystallinity, which allows achieving structural superlubricity. However, water is ubiquitous and often the origin of failure of electro-mechanical devices due to the action of substantial interfacial forces like adhesion and stiction between moving components. Despite the rapid broadening of graphene research in recent years, there is still a lack of molecular level understanding of its interaction with water and other liquids. Strategies to modulate interfacial forces in a liquid environment could help meet future structural and functional requirements of devices. Our work has examined liquid slippage as well as interfacial forces along the graphene plane in several different liquids. In this presentation, I will describe our experimental approach and results, as well as theories and models to interpret these results. Among others, we find a relation between the interfacial ordering of the liquid molecules and liquid slippage, which suggests that the ordering of the liquid molecules on the graphene surface promotes slip. Furthermore, we have found that liquid slippage and friction are sensitive to the substrate underneath graphene. This appears as a strategy to modulate the frictional characteristics of the graphene/liquid interface that we have further examined. The conclusions inferred from these studies should help design lubricants that leverage the synergy between graphene and a fluid.

Biography
Since 2013 Dr. Espinosa-Marzal is an Associate Professor at the University of Illinois at Urbana-Champaign (UIUC) in the departments of Materials Science and Engineering and Civil and Environmental Engineering. In 2016, she was awarded Associate to the Center for Advanced Study at UIUC, in 2019 she received the Deans Award for Excellence in Research and in 2020 she was named Donal Biggar Willet Faculty Scholar. Dr. Espinosa-Marzal has a Ph.D. in materials engineering from Hamburg University of Technology (Germany). After her Ph.D., she received an award to promote academic career of young researchers from the German Research Foundation (DFG), which brought her to Princeton University as a research fellow. Prior to joining Illinois, Dr. Espinosa-Marzal spent four years as senior scientist in the laboratory of surface science and technology in the Materials Science Department at the ETH Zurich in Switzerland. Her research interests include  understanding the molecular mechanisms underlying adhesion, friction, and lubrication. She has published over sixty peer-reviewed manuscripts.  Since 2016, she serves as member of the executive committee of the Division of Colloids and Surface Chemistry at the American Chemical Society in the role of membership secretary. 

Dr. Jean-Francois Molinari

Director, Computational Solid Mechanics Laboratory, Civil Engineering Institute
EPFL, Switzerland

Revisiting Archard's Wear Model: A Dialog Between Scales
Tuesday, November 10, 2020, 1:00 pm

Abstract
We discuss recent advances in developing a fundamental, mechanistic, understanding of the evolution of surface roughness of solids during dry sliding. The time evolution of surface roughness is little understood although it crucially impacts friction and wear. Engineering wear models are for the most part empirical, and the development of physics-based predictive models will require intensive experimental, theoretical and numerical research at various scales. This presentation focuses on atomistic and mesoscale numerical modelling of rough solids under sliding in the presence of adhesive wear mechanisms.

 
In the first part, we summarize our attempts at capturing debris formation at micro contacts using atomistic potentials. We show that, in the simple situation of an isolated micro contact, the final debris size scales with the maximum junction size attained upon shear. This permits to draw analogies with Archard adhesive wear model. In the second part, this single-asperity understanding is incorporated in a mesoscale model, which aims at estimating from first principles the wear coefficient, a notoriously little understood parameter in wear models. We estimate the amount of volume of debris formed for a given applied load, using the probability density of micro contact sizes. A crucial element of this mesoscale model is the distribution of surface heights, which should evolve as wear processes take place. This leads us, in the final part, to a discussion of recent simulations aiming at understanding the long term evolution of surface roughness. These long time scales simulations reveal the emergence of self-affine fractal surfaces irrespective of the initial surfaces characteristics.


Biography
Professor J.F. Molinari is the director of the Computational Solid Mechanics Laboratory (http://lsms.epfl.ch) at EPFL, Switzerland. He holds an appointment in the Civil Engineering institute, which he directed from 2013 to 2017, and a joint appointment in the Materials Science institute. He started his tenure at EPFL in 2007, and was promoted to Full Professor in 2012.

J.F. Molinari graduated from Caltech, USA, in 2001, with a M.S. and Ph.D. in Aeronautics. He held professorships in several countries besides Switzerland, including the United States with a position in Mechanical Engineering at the Johns Hopkins University (2000-2006), and France at Ecole Normale Supérieure Cachan in Mechanics (2005-2007), as well as a Teaching Associate position at the Ecole Polytechnique de Paris (2006-2009).

The work conducted by Prof. Molinari and his collaborators takes place at the frontier between traditional disciplines and covers several length scales from atomistic to macroscopic scales. Over the years, Professor Molinari and his group have been developing novel multiscale approaches for a seamless coupling across scales. The activities of the laboratory span the domains of damage mechanics of materials and structures, nano- and microstructural mechanical properties, and tribology. Prof. Molinari was a recipient of an ERC Starting Grant award in 2009.

Dr. Patricia Iglesias Victoria

Associate Professor, Department of Mechanical Engineering 
Rochester Institute of Technology, Rochester, NY 14623

Protic Ionic liquids:  Economical and Low-Toxicity Lubricants and Additives
Thursday, November 12, 2020 at 9:00 am CT

Abstract
For almost twenty years, Ionic Liquids (ILs) have received the attention of the research community as potential high-performance lubricants and additives. ILs are organic salts with molten temperatures under 100 °C, and they possess unique physicochemical properties. When ILs are used as lubricants or additives, they can contribute to increasing the service life span of engineering systems by forming protective tribofilms between the surfaces in contact. However, most of the ILs currently studied in lubrication are aprotic ionic liquids (AILs), composed of hydrophilic and halogen-containing anions. It is well known that these anions will decompose in the presence of water, liberating toxic and corrosive species. Environmental awareness has increased the need for more environmentally friendly lubricants. In addition, the high cost of AILs has been a major drawback for commercial applications. In this talk, new developments in the use of Protic Ionic Liquids (PILs), a low-cost and low-toxicity group of ILs, as lubricant and additives will be discussed.

Biography
Dr. Patricia Iglesias Victoria is an Associate Professor in the Department of Mechanical Engineering at the Rochester Institute of Technology, New York. Previously she served as Assistant Professor at the National Technical Institute for the Deaf and as Associate Professor at the Polytechnic University of Cartagena, Spain. Dr. Iglesias has also previously held a visiting researcher position with the Materials Processing and Tribology group at Purdue University, Indiana.

Dr. Iglesias received her B.S and PhD in Mechanical Engineering from the Polytechnic University of Cartagena, Spain. Her research focuses on wear and friction of materials, ionic liquids as lubricants and lubricant additives, nanostructured materials and textured surfaces. She is founding director of the Tribology Laboratory  at the Rochester Institute of Technology. Dr. Iglesias has extensive experience working on tribology, and has published more than 60 peer-reviewed articles and conference proceedings in the area.

Dr. David Burris

Associate Professor in Mechanical Engineering at the University of Delaware
Newark, DE 19716

Cartilage Tribology and the Biomechanics of Joint Health
Thursday, November 12, 2020, 1:00 pm CT

Abstract
The most basic questions about how cartilage and joint function remain unanswered despite nearly a century of research. It is unclear why friction coefficients are so low, how cartilage supports stresses 100x larger than its modulus with negligible strain, if the unusual roughness of cartilage has a purpose, and whether rough interfaces are highly permeable or practically impermeable. In this talk, I will review what we have learned about these questions over the last decade, new insights into cartilage functionality, and what they imply about how one can promote joint health. I will start by demonstrating that the lubrication is driven by near-surface strain and hydration - as far as we can tell, high friction is impossible under low strain surface conditions and low friction is impossible under high strain surface conditions. Next, I will demonstrate how a structural trick allows cartilage, an extremely soft biomaterial, to carry enormous stresses with minimal strain; this ability is the key to cartilage lubricity under high stress in vivo conditions. Finally, I will discuss how the joint uses movement to manage load-driven fluid loss; the effect we demonstrate is analogous to driving your car to reinflate a leaky tire. Finally, I will discuss low risk strategies everyone can use to maximize cartilage function and maintain joint health.

Biography
Dr. David Burris is an Associate Professor in Mechanical Engineering at the University of Delaware. He has published 4 patents and 74 peer-reviewed journal publications with over 3500 citations. He is the recipient of the ASME Marshall B. Peterson award, the ASME Burt L. Newkirk award, the ASME Pi Tau Sigma Gold Medal, the AFOSR Young Investigator award, the University of Florida Outstanding Young Alumnus award, and the University of Delaware Mid-Career Faculty Excellence in Scholarship award.

Dr. Izabela Szlufarska

University of Wisconsin - Madison
Madison, WI 53706

Microstructural and Chemical Evolution of Frictional Contacts
Friday November 13, 2020 at 9:00 A.M.

Abstract

A critical challenge in designing materials with superior tribological properties is the limited understanding of how the contact interface and the microstructures of contacting materials evolve during sliding. This evolution may include grain growth and refinement, evolution of dislocation networks, interaction of dislocations with interfaces, chemical mixing etc. All these phenomena can contribute to energy dissipation (friction) and they can affect the dominant type and amount of wear. The challenges of imaging buried interfaces, particularly in operando, make computer simulations an essential tool. However, while computer simulations can bring valuable insights into interfacial phenomena and mechanisms that control friction, the contact evolution occurs on multiple time scales and length scales and therefore new multiscale and multi-physics approaches are needed to understand contact evolution.

In this talk, I will summarize the present understanding of the how the microstructure of metallic contacts evolves during sliding and how this evolution can be controlled. I will also discuss how mechano-chemical changes that occur in contacts at the molecular scale, can have a significant impact on friction and adhesion of macroscale contacts, including geological slip in crustal faults. Some promising future directions in modeling of mechano-chemical and microstructural evolution of contacts will also be discussed.

Biography
Izabela Szlufarska is a Harvey D. Spangler Professor of Engineering at the University of Wisconsin-Madison and the chair of the Materials Science & Engineering Department. Szlufarska develops and employs theoretical and computational tools to address problems in the areas that span mechanical behavior of materials, interfacial chemistry, and materials design for extreme environments (corrosion, high temperature, radiation). Szlufarska published well over 100 peer-reviewed papers, including multiple publications in Science and Nature journals. Among her awards are NSF CAREER award, Air Force Office of Scientific Research Young Investigator Award, H.I. Romnes Faculty Fellowship, and Vilas Associate Professorship. She was also placed on the National Academy of Engineering list of Frontiers of Engineering. Prof. Szlufarska has served in a number of leadership and advisory roles, including service as a chair of the Materials Research Society meeting (2016), panel lead for the Department of Energy workshop on basic research needs for future nuclear energy, and as the Editor-in-Chief for the journal of “Current Opinion in Solid State and Materials Science”.

Dr. John A. Rogers

Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering,
Biomedical Engineering and Medicine, Northwestern University
Evanston, IL 60208

Electronic and Microfluidic Systems That Softly Interface to the Skin
Friday, November 13, 2020, 1:00pm CT

Abstract

Recent advances in materials, mechanics and manufacturing establish the foundations for high performance classes of electronics and other microsystems technologies that have physical properties precisely matched those of the epidermis.  The resulting devices can softly integrate with the surface of the skin in a physically imperceptible fashion, to provide continuous, clinical-quality information on physiological status.  This talk summarizes the key ideas, including those related to interfaces, fatigue properties and biotribology.  Specific examples include wireless, battery-free electronic 'tattoos' for continuous monitoring of vital signs in neonatal and pediatric intensive care; and microfluidic/electronic platforms for capturing and performing biomarker analysis of microliter volumes of sweat in sports and fitness.

Biography
John A. Rogers is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Medicine at Northwestern University, with affiliate appointments in Mechanical Engineering, Electrical and Computer Engineering and Chemistry, where he is also Director of the recently endowed Querrey/Simpson Institute for Bioelectronics.  He has published more than 750 papers, is a co-inventor on more than 100 patents and he has co-founded several successful technology companies.  His research has been recognized by many awards, including a MacArthur Fellowship (2009), the Lemelson-MIT Prize (2011), the Smithsonian Award for American Ingenuity in the Physical Sciences (2013), the MRS Medal (2018) and most recently the Benjamin Franklin Medal from the Franklin Institute (2019).  He is a member of the National Academy of Engineering, the National Academy of Sciences, the National Academy of Medicine, the National Academy of Inventors and the American Academy of Arts and Sciences.