Study on pre-charge loss for application of pre-charging method to electrostatic micro-actuators

Abstract

High actuation voltage which reaches tens of volts is the bottleneck in the electrostatic actuators field. Pre-charging method has proposed to solve this problem. This novel method can dramatically reduce the actuation voltage while maintaining the large contact-force. However, this previous work has limitation to apply it to micro-actuators. The retention time performance is too short and vertical-type structure has not yet been demonstrated. Therefore, this thesis analyzes the precharge loss problem to prolong the retention time and realizes the pre-charging system with vertical-type microelectromechanical switch. In conclusion, we can improve the retention time by utilizing Benzocyclobutene (BCB) substrate and charge-tank structure. Furthermore, we demonstrate the vertical-type pre-charging system through measuring the actuation voltage and contact-resistance, depending on the pre-charging voltage level.