Design and Simulation Optimization of a Torsional MEMS Electric Field Sensor Based on Piezoelectric Drive
Power sensing technology is the key to realizing the digital transformation of the new power system,where the electric field parameter is one of the important monitoring objects.A torsional micro-electro-mechanical system(MEMS)electric field sensor based on piezoelectric drive was proposed.The MEMS electric field sensor was driven by a drive structure to realize the modulation measurement of electric field by periodically vibrating the shielding electrode on the surface of the sensing electrode.The piezoelectric drive structure consisted of four symmetrically distributed L-type piezoelectric cantilever beams,and two pairs of staggered-coupled comb electrodes at the shielding electrode and the sensing electrode.Then the solid mechanics-electrostatic coupling model of the structure was established by COMSOL simulation software,and the resonance frequency and vibration amplitude of the sensitive structure were calculated.The results show that the resonance frequency of the structure can reach 25 047 Hz in the operating mode,and the end displacement of the shielding electrodes is 85.06 μm under an AC driving voltage of 3 V.Furthermore,the key parameters of the sensitive structure were simulated and analyzed by parameter scanning.The parameters such as the length,width,spacing and number of comb electrodes as well as the length of the induction electrode,the width of the induction electrode,the number of comb electrodes and the spacing of the induction electrodes were optimized.Finally,the testing of the sensor was completed.The test results show that the sensitivity of the sensor is 3.24 mV/(kV/m)with a maximum measurement error of only 3.75％.
micro-electro-mechanical systems(MEMS)electric field sensorspiezoelectric actuationCOMSOL
万方数据
维普
