Self-oscillation mode due to fluid-structure interaction in a micromechanical valve

This letter presents an original actuation mode for a micromechanical valve based on the induction of a self-oscillation, provided by the strong coupling between a mobile mechanical part and the fluid flow. The presented structure consists of a rigid silicon pad processed on a flexible membrane, both located over a silicon microchannel with structured internal walls. A theoretical analysis, based on a combination of the small perturbations method and a numerical study, shows that a self-oscillation can be induced on the mobile part due to the hybridization of the first flexion and torsion resonance modes interacting with the gas flow. Characterization of the self-oscillating microvalve shows high performances without electric energy supply for control.