Sameh Tawfick1,2, Yichao Tang3. 1. Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Il 61801, USA. tawfick@illinois.edu. 2. The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Il 61801, USA. 3. Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Il 61801, USA.