Research Of MOEMS Scanning Mirror Integrated With Angle Sensor

MOEMS based mirrors as key building blocks of micro-opto-electro-mechanical systems are widespread applied in lots of areas, such as optical communications, display technology, adaptive optics, spectral analysis technology, .etc. MOEMS mirrors are small in size, low in power-consumption and suitable for mass production with low-cost, in comparison with conventional motor-driving reflection mirrors. Therefore, they become one of the MOEMS research hotspot. Microspectrometers, medical imaging and barcode reader require MOEMS mirrors to have large reflection area, big scanning angle,low power consumption and precision control. Therefore, study on micromirrors with large area and big scanning angle, achievement of integration of angle sensor and micromirror, and closed-loop control of the scanning mirror are proposed, which is significant for research and application.This dissertation focuses on the development of MOEMS based mirrors integrated with angle sensor facing to application of micro-spectrometers. Achievements include structure design, establishment of theoretical model, simulation and optimization, key fabrication technique and encapsulation design. The sample of the micromirror is developed. Moreover, a control method of the mirror and a function testing approach of the mircromirror are also studied. Main content of the dissertation are given following:1. Consult the research status of MOEMS mirrors, and analyze operation principles, merits and shortcomings of typical micromirrors. Aiming at application for micro-spectrometers and surmounting of weak points of previous mircromirrors, research content of a MOEMS mirror integrated with angle sensor is determined.2. A novel structure of a MOEMS based micromirror integrated with angle sensor is proposed. Analysis of operation principles of micromirror and angle sensor, dynamic mechanical model of the system and theoretical model of actuator and angle sensor, and simulation and optimization of the micromirror structure utilizing FEA approach are developed.3. Layout of the micromirror is designed. And design of process flow including of the micromirror is based on research of key microfabrication techniques of the mirror. Then, micromirror chips are fabricated. Moreover, two approaches of magnetic circuit are proposed, and magnetic analysis is conducted. Finally, package of the micromirror is designed. 4. Study on the driving and control circuit of the mirror. Design of signal producing module, angle detecting module, feedback control module and variable gain amplifier module are conducted, respectively. Then the driving control circuit is built and debugged.5. Study on a function testing approach of the micromirror, and the testing platform is established. The resonant frequency, scanning angle of the micromirror, sensitivity and resolution of the angle sensor are tested. Results show that resonant frequency and quality factor of the MOEMS with reflected area of 5×6mm~2 are 543.22Hz and 180.8, respectively; when the driving voltage is 0.65Vrms, the scanning angle of the mirror achieves±12.3°; the sensitivity and resolution of the mirror are 0.35V/°and 0.5', respectively.