Paper
8 September 2011 A novel electromagnetically actuated MEMS scanning mirror integrated with rotation angle sensor
Li Chen, Zhi-yu Wen, Zhong-quan Wen, Rong-rong Qian
Author Affiliations +
Abstract
Aiming at application of micro-spectrometer systems, a novel electromagnetically actuated MEMS scanning mirror with large size and integrated rotation angle sensor is proposed for the application of micro-spectrometer. The size of the mirror plate is 6x5mm2, which is supported by two torsion beams. The scanning mirror is fabricated on a 500 μm-thick single crystal silicon wafer using bulk micromachining process. Two gold coils are deposited on back side of the mirror using electroplating technology. One of them is used to generate Lorentz force to drive the mirror, and the other is used to monitor the rotation angle by measuring the induced voltage which is proportional to the angular rate. The silicon substrate is heavily doped (0.02 ohm•cm) to connect the coil central end to outside pad. A 500 nm-thick aluminum film is sputtered on the front side of the mirror plate to form a high quality mirror surface. The whole structure is released by wet etching technology, and corner compensation structure is designed to avoid convex corner undercutting. In order to achieve large deflection angle, NdFeB permanent magnets are used to provide high magnetic field. Testing results show that maximum mechanical rotation angle of the scanning mirror can achieve ±10°at the resonant frequency of 344Hz with low driving voltage of less than 1Veff, corresponding to a Q-factor of 137 at atmospheric pressure, and the output voltage of the angle sensor has high linearity.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Li Chen, Zhi-yu Wen, Zhong-quan Wen, and Rong-rong Qian "A novel electromagnetically actuated MEMS scanning mirror integrated with rotation angle sensor", Proc. SPIE 8191, International Symposium on Photoelectronic Detection and Imaging 2011: Sensor and Micromachined Optical Device Technologies, 819125 (8 September 2011); https://doi.org/10.1117/12.901043
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KEYWORDS
Mirrors

Microelectromechanical systems

Sensors

Silicon

Magnetism

Micromirrors

Semiconducting wafers

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