1. Graduate School of Advanced Science and Engineering; Waseda University; TWIns, 2-2 Wakamatsu-cho, Shinjuku Tokyo 162-8480 Japan
2. Center for Micro-BioRobotics@SSSA; Istituto Italiano di Tecnologia; Viale Rinaldo Piaggio 34 Pontedera, Pisa 56025 Italy
3. Waseda Institute for Advanced Study; Waseda University; 1-6-1 Nishi Waseda, Shinjuku-ku Tokyo 169-8050 Japan
4. Japan Science and Technology Agency; PRESTO; 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan