1. Department of Chemistry, and The Alan G. MacDiarmid Nanotech Institute, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080, U.S.A.
2. Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Polytechnic Institute and State University, 310 Durham Hall, Blacksburg, Virginia 24061, U.S.A.
3. Department of Materials Science and Engineering, Department of Mechanical Engineering, Department of Bioengineering, and The Alan G. MacDiarmid Nanotech Institute, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080, U.S.A.