This paper presents the design and evaluation of a high force density fishbone shaped electrostatic comb drive actuator. This comb drive actuator has a branched structure similar to a fishbone, which is intended to increase the capacitance of the electrodes and hence increase the electrostatic actuation force. Two-dimensional finite element analysis was used to simulate the motion of the fishbo...

Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. State-of-the-art electrostatic actuators achieve maximum deflections of approximately one third of the electrode separation. Large electrode separation and high driving voltages are normally required to achieve large actuator movements. Here we rep...

Presented in this paper is a bi-directional out-of-plane actuator which combines the merits of the electrostatic repulsive principle and the electrostatic attractive principle. By taking advantage of the electrostatic repulsive mode, the common “pull-in” instability can be lessened to enlarge the displacement, and by applying the electrostatic attractive mode, the out-of-plane displacement is f...

We have studied a stacked-type electrostatic actuator by folding two ribbon electrodes in an alternate configuration. The energy efficiency of this type of actuator was investigated using the thick-electrode-part actuator and triangle-shaped actuator. The maximum energy efficiency levels were 30–40% for the thick-electrode-part actuator and 40–50% for the triangle-shaped actuator.

Electrostatic comb-drive actuators have been developed and employed for many applications. However, side stability (side pull-in) limits the actuator stroke constraining its applications. Hence, extending the stable traveling range is an important issue for designing electrostatic comb-drive actuators. This study presents a novel cascade electrostatic comb-drive actuator. Instead of shifting th...

This paper presents a high-bandwidth capacitance estimation and driving circuit especially tailored for its use with MEMS electrostatic actuators. The circuit can be integrated as a part of a system comprising an electrostatic actuator to provide self-testing and failure prediction capabilities and also as a simple and low-cost actuator dynamics characterization system capable of measuring both...

In this paper we present an electronic circuit for position or capacitance estimation of MEMS electrostatic actuators based on a switched capacitor technique. The circuit uses a capacitive divider configuration composed by a fixed capacitor and the variable capacitance of the electrostatic actuator for generating a signal that is a function of the input voltage and capacitive ratio. The propose...