Biological materials employ diverse strategies for maintaining robustness against extreme mechanical environments, which generally stem from carefully tailored molecular interfaces and microstructures. In this talk, I will summarize recent advances in computational design of new polymeric materials that make use of nanoscale topologies that result in improved mechanical properties. I will first present physics-based and datadriven approaches that we developed describe molecular and mesoscale mechanics of polymer thin films and nanocomposites. Following this, I will present three distinct strategies for achieving impact tolerance in soft materials. The first strategy takes inspiration from helicoidal, imbricated Bioligand microstructures found in natural shells and armor materials, which results in superior impact response. The second strategy involves the use of star polymers and polymer grafted nanoparticles to improve diametric mechanical properties such as modulus and toughness, while also changing the timedependence of the mechanical response. The final strategy involves creating nanoparticle interfaces that take inspiration from catch bonds in biological adhesion proteins, which results in molecular seat-belt type interfaces that self-strengthen at high strain rates, in a way similar to shear-thickening fluids. I will conclude with some thoughts on how to translate these theoretical findings to new material concepts that could be explored further with synergistic experiments and simulations.
Sinan Keten is the June and Donald Brewer Professor of Civil & Environmental Engineering and Mechanical Engineering at Northwestern University. He joined Northwestern University faculty in 2010 after obtaining his Ph.D. from MIT. His research expertise is on computational materials design and mechanics with an emphasis on soft matter, and he has co-authored over a hundred journal articles in this area. Prof. Keten has received a number of honors including the Presidential Early Career Award for Scientists and Engineers (PECASE), Office of Naval Research (ONR) Young Investigator Program (YIP) Award, Society of Engineering Science Young Investigator Medal, ASME Sia Nemat Nasser Award, ASCE Huber Prize. He is a Fellow of the American Physical Society and serves as an Associate Editor for the Journal of Applied Mechanics and npj Computational Materials.
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