The 2015 AMMCS-CAIMS Congress
Interdisciplinary AMMCS Conference SeriesWaterloo, Ontario, Canada | June 7-12, 2015
AMMCS-CAIMS 2015 Plenary Talk
Multiscale Modeling of Soft Materials and Related Biological Responses
Wing Kam Liu (Northwestern University)
Liquids, polymers, gels, foams and a number of biological materials are soft materials, which can be easily deformed by thermal stress or thermal fluctuations. Predominate physical behaviors of these soft materials occur at energy scale comparable with room temperature thermal energy. These behaviors cannot be, or are not easily, to be directly predicted from its atomic or molecular constituents. This is because the soft materials are always self-assemble into mesoscopic structures, which are much larger than the microscopic scale, and yet much smaller than the macroscopic scale of these materials. Especially, the mechanical and physical properties of soft materials originate from the interplay of phenomena at different spatial and temporal scales. As such, it is necessary to adopt multiscale methods when dealing with soft materials in order to account for all important mechanisms. The offerings of this lecture are twofold: (1) establishing a multiscale modeling framework to predict viscoelastic behaviors of polymers through fractional derivatives, (2) rapid computational prototyping and testing of drug carriers in tumor microvasculature through immersed molecular finite element method (IMFEM). In (1), we have incorporated the fractional diffusion of free chains into the integration kernel for the viscoelastic response of polymers and polymer nanocomposites using the Mittag-Leffler function. While conventional models for viscoelastic materials employ a discrete relaxation spectrum, the fractional-order model exhibits a continuous relaxation distribution, which is in accordance with experimental observations. In (2), the IMFEM is used to simulate the whole blood including blood plasma, red blood cells and nanoparticles. We elucidate how the size, shape and stiffness of nanoparticles will affect their dispersions in the microvasculature, with the accurate molecular interactions informed by molecular mean-field theory.
Dr. Wing Kam Liu, Walter P. Murphy Professor of Northwestern University, has made fundamental, innovative contributions to the theory, methodologies, and applications of multiscale simulations towards the understanding and design of nano-materials, polymers science, and multiresolution mechanics. His ISI and Google citations and H factors are (14,200, 60) and (37,750, 88), respectively. In 2014, Liu is selected as a highly cited researcher in Computer Science and a member of the World’s Most Influential Scientific Minds by Thompson Reuters. Liu developed new exceptional accuracy meshfree methods for simulation of extremely deformation of solids and fluids including additive manufacturing; fractional-order viscoelasticity polymer science; fluid-structure interaction, and applicable to medical imaging. He was the PI of a multi-year multi-million research grant from Goodyear Tire and Rubber Company to develop and integrated design strategy to enable prediction, synthesis and characterization of new polymer nanocomposites to achieve enhanced performance. Liu is current the President of IACM and Chair of USNCTAM; Founding Director of the Summer Institute on Nano Mechanics and Materials; Founding Chair of the ASME NanoEngineering Council; Editors of Computational Mechanics & Int. J. of Applied Mathematics and Mechanics; Honorary Editor of Int. J. of Computational Methods; serve on numerous editorial boards; Consultant to 20+ organizations. Liu has written three books; and he is a Fellow of ASME, ASCE, USACM, AAM, and IACM. Liu’s selected awards and honors including: 2014 Japan Society for Computational Engineering and Science Grand Prize in recognition of his outstanding contributions in the field of computational mechanics; the Honorary Professorship from Dalian University of Technology in 2013; the 2012 IACM Gauss-Newton Medal; the 2012 ASME Design Automation Conference Best Paper Award; the 2009 ASME Dedicated Service Award, the 2007 ASME Robert Henry Thurston Lecture Award, the 2007 USACM John von Neumann Medal, the 2004 JSME Computational Mechanics Award, the 2002 IACM Computational Mechanics Award, the 2001 USACM Computational Structural Mechanics Award, the 1995 ASME Gustus L. Larson Memorial Award, the 1985 ASME Pi Tau Sigma Gold Medal, the 1979 ASME Melville Medal, the 1989 Thomas J. Jaeger Prize of the ISMIRT, and the 1983 Ralph R. Teetor Educational Award, American Society of Automotive Engineers.