Vibration-Induced Frequency-Controllable Bidirectional Locomotion for Assembly and Microrobotic Applications

This paper describes vibration-induced bidirectional locomotion of a milliscale cylindrical body. Using a laterally vibrating platform, we achieved a frequency controlled bidirectional movement by attaching two polydimethylsiloxane cylindrical rods with microscale ratchet-shaped legs of different densities facing in opposite directions. The polymeric body (2 times 2 times 20 mm³) was placed on a glass slide covered by thin lubricating oil and vibrated at a constant amplitude of 0.2 mm. The micromobile composite cylinder changed its direction of motion at a cross-over frequency of 156 Hz. The cross-over phenomena is due to the difference between static and kinetic friction coefficients of the two opposing parts.