Study on dynamic actuation in double microcantilever-based electrostatic microactuators with an in-house experimental set-up

Abstract

This paper investigates the effect of dynamic excitation and its utility for enhancement of stable displacement range for a double cantilever-based electrostatic microactuator. A coupled electromechanical problem has been formulated using Galerkin method and solved considering dynamic actuation. The effect of excitation frequency is analyzed thoroughly to estimate the maximum stable displacement range of the actuator. Extensive studies illustrate that for suitable ac voltage–frequency combination, the maximum stable tip deflection for the cantilevers can be obtained even in the range of 50% to 90% of initial gap under specific damping. Such inherent dynamic characteristic of the actuator has been exploited here to achieve larger travel range. Furthermore, the theoretical observation has been experimentally demonstrated with a double microcantilever-based structure fabricated using silicon-on-insulator based process. The experimentation has been carried out using a developed in-house set-up. The major advantage in the present study is that unlike reported literature, the extended range has been achieved here without any additional complex circuits or design modifications. The proposed concept can be extended further to improve the displacement range of other microstructures toward different applications.