A flexible model for studying fringe field effect on parallel plate actuators

Abstract

Electrostatic parallel plate actuators are common in micro-electro-mechanical systems due to their compatibility with micro-fabrication technology. Parallel plate actuators suffer from an instability problem called the pull-in phenomenon that happens when the applied DC voltage exceeds a certain value called the static pull-in voltage. The value of this critical voltage is important in many applications that depend on parallel plate actuators such as switches and static gas sensors. The fringe field around the edges of the plates could severely affect the performance of the actuator. This paper introduces a new model for the parallel plate actuator to calculate the value of static pull-in voltage. The proposed model considers the fringe field between the two plates. The static pull-in voltage of some PolyMUMPs actuators is practically measured and compared to the simulation results that involve the fringe field effect. The model is simulated using MATLAB to show the influence of that field on the static pull-in voltage. The MATLAB results of the proposed model are validated with ANSYS.

Electromechanical Actuators for Haptic Feedback with Fingertip Contact

“…This simple design makes it possible to reduce the diameters to as small as 100 µm and beyond, which is particularly suitable for producing micro-electro-mechanical systems (MEMSs) [62][63][64]. However, with the movable planes driven by the electrostatic force and the interactions between the mechanical and electrostatic forces, it is possible for pull-in instability, which is when the two plates collide with each other or even initiate collapse [65,66]. Most research studies on utilizing electrostatic actuators to provide haptic feedback focus on soft dielectric elastomers.…”

A Review of Actuation and Sensing Mechanisms in MEMS-Based Sensor Devices

“…Some types of electrostatic actuation must be carefully considered when studying MEMS under electrostatic actuation. The most prevalent forms are based on either capacitor consisting of two simple parallel plates or a comb-drive structure consisting of multiple interdigitated or non-interdigitated fingers [ 72 , 73 ]. A conventional method [ 74 ] is the parallel plate actuation in which the top moving plate has a certain polarity, and the bottom fixed plate has an opposite polarity (Fig.…”