Design, fabrication, and characterization of out-of-plane W-form microsprings for vertical comb electrodes capacitive sensor

摘要

The vertical comb electrodes capacitive sensor u0001VCECSu0002 hasnbeen widely used in inertia sensors, resonant sensors, and pressurensensors, etc. In this paper, we present an improved microspring, called anW-form spring, that provides a large stiffness ratio in an out-of-planendirection while retaining a long sensing range for a VCECS. The stiffnessnratio, defined as the ratio of the stiffness in the lateral direction to thenout-of-plane direction, is an important parameter for determining the sta-nbility of the VCECS. To realize the properties of the W-form spring, suchnas the spring constant and stiffness ratio, theoretical analysis and nu-nmerical simulations are performed. In addition, VCECSs with W-formnand other springs have been fabricated using microelectromechanicalnsystems u0001MEMSu0002 micromachining technology. The spring constants ofnthe sensor have been calculated from simulations and measured results.nThe characteristics among different suspension springs are compared.nAccording to the numerical simulations and experiment results, the work-ning range and stability of the device are both improved for the VCECS bynusing the W-form suspension spring