Temperature Compensation for MOEMS Micromirror with Piezoresistive Angle Sensor

Assuring MOEMS micromirror work with well-controlled deflection angle in varying environmental condition is of vital importance in practical application. To solve this problem, we develop an electro-magnetically driven micromirror with piezoresistive angle sensor, which is conjunct with platinum resistance temperature detector. The proposed n-type piezoresistive angle sensor is placed on the torsion beam of micromirror to monitor the rotation angle. The test results show high sensitivity of 10.86 mV/° with 3.3V power supply, but it exhibits instability at different temperature. Then the platinum resistance temperature sensor is integrated as an accurate solution for local temperature compensation. It shows linear response with slope of $1.207\ \Omega/{{}^{\circ}}\mathrm{C}$ to temperature excitation. The device is calibrated and tested in environmental chamber to apply temperature variation over a range from −20 °C to 75 °C. After compensation, the mechanical angle error of micromirror is 0.943° compared to uncompensated one of 3.21°.