Surface roughness-induced speed increase for active Janus micromotors† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5cc01607j Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.

aMax-Planck Institute for Intelligent Systems. Heisenbergstr.3, 70569 Stuttgart, Germany. bInstitute of Energy Technologies, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia, Spain. cDepartment of Physics and Astronomy, Northern Arizona University, S. San Francisco Street, Flagstaff, Arizona 86011, United States dInstituci Catalana de Recerca i Estudis Avancats (ICREA), Passeig Lluís Companys 23, 08010, Barcelona, Spain eInstitut de Bioenginyeria de Catalunya (IBEC), Baldiri I Reixac 10-12, 08028 Barcelona, Spain fInstitute for Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany *Email: [email protected] ‡These authors contributed equally to the work.