Figure 1: Scanning electron micrographs showing nanostructured surface produced by electron-beam lithography applied to bilayer resist layer on SiO2, consisting of lift-off resist (LOR) and polymethylmethacrylate (PMMA). Following electron-beam exposure and development, the PMMA layer was made hydrophilic by oxygen-plasma ashing followed by trimethylchlorosilane (TMCS) derivatization of the exposed SiO2. The nanoscale track illustrated here has similar walls as the motility supporting open areas illustrated below (e.g., Figure 4).