Design of a microelectromechanical systems resonant electric field sensor with sensitivity robustness

• Main Authors: Heng Liu, Jia-qi Xu, Feng Xiong, Rui-li Meng
• Format: Article
• Language: English
• Published: SAGE Publishing 2015-12-01
• Series: Advances in Mechanical Engineering
• Online Access: https://doi.org/10.1177/1687814015619829

Studies indicate that driving circuit and drift error in resonance frequency influence the sensitivity of micromechanical resonant electric field sensors. This study proposes an electric field sensor with a comb structure for driving and sensing. A dynamic model is built for the microsensor, which analyzes the behavior and sensitivity of the system on different closed-loop self-excited circuits using the averaging method. Theory and simulation results show that with the use of a proportional–integral controller, the sensitivity remains constant regardless of the variations in the resonance frequency of the shielding layer and Q-factor. The sensitivity is higher with a suitable proportional–integral controller than without a proportional–integral controller. If the parameters of the proportional–integral controller fail to satisfy the constraint relationship, output voltage becomes unstable, and the sensitivity is distorted.