Seminar - Nanomechanics of Engineering and Biological Systems by Prof. Huajian Gao
Date: 19 December 2012 (Wednesday)
Time: 10:30 am
Venue: Y410, The Hong Kong Polytechnic University
Nanomechanics is a highly interdisciplinary field that attempts to combine the state-of-the-art experimental techniques and unprecedented computing power to probe unique mechanical properties of materials at nanoscale. As examples of recent progresses in this field, I will describe two sets of recent research on nanomechanics of engineering and biological system conducted by my research group and our collaborators. The first is concerned with the study of high strength, high ductility metallic nanostructures. Here, we report a combined theoretical and experimental study on ductile vs brittle deformation and fracture behaviors in nanotwinned nanopillars, with results indicating a unique twin-spacing-induced ductile-brittle transition mechanism in such systems . The second has to do with how 1D and 2D nanomaterials such as nanotubes, nanowires, nanofibers and graphene enter human and animal cells via unique tip/corner/edge entry pathways . This topic is of urgent societal concerns since the rapid developments of nanotechnology have led to the projection that the coming decades may see release of hundreds even thousands of tons of nanomaterials into the environment, and high aspect ratio 1D and 2D nanomaterials are known to cause frustration of human and animal cells, which can further cause inflammation and cancer as in the case of asbestos.
1. D.C. Jang, X.Y. Li, H.J. Gao and J.R. Greer, “Deformation Mechanisms in Nanotwinned Metal Nanopillars,” 2012, Nature Nanotechnology, Vol. 7(9), 594–601.
2. X.H. Shi, A. von dem Bussche, R.H. Hurt, A.B. Kane and H.J. Gao, “Cell Entry of One-Dimensional Nanomaterials Occurs by Tip Recognition and Rotation,” 2011, Nature Nanotechnology, Vol. 6(11), pp. 714–719.
Huajian Gao received his B.S. degree from Xian Jiaotong University of China in 1982, and his M.S. and Ph.D. degrees in Engineering Science from Harvard University in 1984 and 1988, respectively. He served on the faculty of Stanford University between 1988 and 2002, where he was promoted to Associate Professor with tenure in 1994 and to Full Professor in 2000. He served as a Director at the Max Planck Institute for Metals Research between 2001 and 2006 before joining the Faculty of Brown University in 2006. At present, he is the Walter H. Annenberg Professor of Engineering at Brown.
Professor Gao’s research is focused on the understanding of basic principles that control mechanical properties and behaviors of materials in both engineering and biology. He is an author/co-author of more than 300 scientific papers with total citations exceeding 12K and an h-index of 59. He is a Member of the National Academy of Engineering of USA and a co-editor-in-chief of the Journal of the Mechanics and Physics of Solids, the flagship journal of his field. He is also the recipient of numerous academic honors, from a John Simon Guggenheim Fellowship in 1995 to recent honors including the Alexander von Humboldt Prize from Germany and Rodney Hill Prize in Solid Mechanics from the International Union of Theoretical and Applied Mechanics in 2012.