An Electrothermal Micromirror Array Integrated with Thermal Convection-Based Mirror Position Sensors

A novel electrothermal micromirror array integrated with thermal convection-based mirror position sensors is proposed, in which a heater is integrated on the mirror plate to generate a temperature distribution that will be changed by the movement of the mirror plate. The temperature change is then picked up by the thermistors integrated on the substrate. Both the displacement and the tip-tilt angle can be detected. A 3×3 micromirror array has been successfully fabricated. Experiments show an average sensitivity value of 8.6 mV/μm in the displacement range of 50 μm to 150 μm, and an average sensitivity of 95.5 mV/° in the angular scan range of 2° to 10°.