A Novel MEMS Actuator Driven with a Low DC Voltage

Abstract

In this paper, we propose a novel MEMS actuator that can achieve a relatively large in-plane displacement of 5 μm or more driven with a low dc voltage of 3.3 to 5.0 V to ensure compatibility with integrated circuits and microcontroller unit (MCU) boards. The drive mechanism is based on a comb-shaped electrostatic microactuator. However, in general, the electrostatic type can achieve only a small amount of displacement in spite of a large driving voltage. On the other hand, by vacuum-sealing a device with such an actuator to reduce air resistance and performing ac driving at the resonant frequency of the device, the driving voltage can be considerably reduced. However, in the case of devices that need to be driven with dc voltages, such as RF switches, 2D optical raster scanners, optical switches, and various sensors, displacement is not amplified even if operating in a vacuum environment. Moreover, it would be strongly desirable to control these devices directly using integrated circuits and MCU boards without any external driver boosters or power supplies. In this paper, we demonstrate that a 6 μm in-plane displacement can be achieved with a dc driving voltage of less than 8.0 V by using a pull-in phenomenon and multiple spring-mass systems based on a comb-shaped electrostatic MEMS actuator.