Abstract:  Advanced nanostructures provide unprecedented access to fundamental length scales in electro-thermal transport. Experimental observations in such materials often contradict established notions and theoretical assumptions. In this talk, I will describe our recent research on two silicon nanostructures of current interest: rough silicon nanowires1-3 and polysilicon inverse opals4. In rough nanowires, our work critically examines the robustness of the Casimir limit for phonon heat conduction and points out the overlooked role of phonon drag. In polysilicon inverse opals, we examine the interplay between grain boundary and surface scattering for electrons and phonons. I will discuss how the fundamental insight gained from these studies could open pathways leading to improved thermal management, energy conversion and storage technologies and our efforts in that direction. Hochbaum et al., Nature, 451, 163 (2008); J.S. Sadhu and S. Sinha, Physical Review B, vol. 84, 115450 (2011); M. Seong, J. S. Sadhu, J. Ma, M.G. Ghossoub and S. Sinha, J. Applied Physics, vol. 111, 124319 (2012). J. Feser et al, J. Appl. Phys., 112, 114306 (2012); M.G. Ghossoub et al., Nano Letters (2013); J.S. Sadhu et al., In review (2013). K. Balasundaram et al.,  Nanotechnology 23, 305304 (2012). J. Ma and S. Sinha, J. Appl. Physics, 112, 073719 (2012); J. Ma et al., Nano Lett. (2013).   Biography:  Sanjiv Sinha is an Assistant Professor in the Department of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign. His research interests are in electro-thermal transport phenomena, thermal management, energy conversion and storage. Prof. Sinha received a B.Tech degree in Mechanical Engineering from the Indian Institute of Technology, Delhi in 1999 along with the Institute Silver Medal. He received the Herbert Kunzel Stanford Graduate Fellowship to pursue the M.S. (2001) and Ph.D. (2005) degrees in Mechanical Engineering at Stanford University. He also received the Intel Ph.D. Fellowship during his graduate studies. Subsequently, he worked at Intel Labs in Oregon. Prof. Sinha did post-doctoral research at the University of California, Berkeley from 2007 to 2008. Prof. Sinha’s research has been recognized through an NSF CAREER award in 2010 and a DARPA-Young Faculty Award in 2011.