Enhanced Fluid Flow by Wavelike Excitation of a Micromechanical Bending Actuator

We present a study on a micromechanical bending actuator, which is intended for creating fluid flow by a fish-like, undulatory motion. This motion pattern describes an ascending wave traveling along the actuator and is capable to shed vortices into the surrounding fluid, forming a vortex wake. A segmented electrode at the top of the bending actuator enables the undulatory excitation. It turns out, that undulation creates slightly higher mass flow than resonant oscillations in the structure's first eigenmode. At the same time, undulation needs less energy for generating equal mass flow, and, hence, is more efficient compared to resonant motion.