Asymmetric charge transfer phenomenon and its mechanism in self-excited electrostatic actuator

We observe the asymmetric charge transfer phenomenon and present its mechanism in self-excited electrostatic actuator for the first time. When a conductive cantilever is excited into oscillation between two electrodes under DC voltage, it is observed to transfer more charge when it contacts the negative electrode than the positive electrode. The mechanism of this asymmetric charge transfer phenomenon is investigated and it is indicated that the amount of the transferred charge, which is directly related to output power, increases with the applied DC voltage and the parasitic capacitance at the fixed end of the cantilever. As such, this work provides further understanding and guidance for output power optimization design of the self-excited electrostatic actuator.