Low-noise real-time measurement of the position of movable structures in MEMS

摘要: Abstract A low-noise, low-perturbing electrostatic position measurement system for capacitive MEMS sensors is described. small-amplitude, high-frequency voltage signal applied between the movable and fixed plates of sensing capacitance. The resulting current modulated by external forces to structure. This high-frequency-shift makes it possible filter low-noise contributes minimize readout perturbations on device. Experimental results are reported a comb-type test structure with quasi-static, sinusoidal, impulsive forces. Resolution long-term stability nanometric values have been obtained.