The Research Of Driving Control Technology Based On Electrothermal MEMS Micromirror

Micro-electromechanical systems (MEMS) with the characteristics of high integration, small size, low power consumption, low price and stable performance are being gradually replace traditional mechanical structure and circuit electronic components. The main application areas related to information and communications, automation, aerospace, biochemistry, medical equipment, consumer electronics and military products.This paper first introduces the theory and applications of electrothermal MEMS micromirror based on reversal series bimorph and folded dual-S-shaped structure. It describes the driving principle in detail and analyzes the internal relationship between the actuator deformation and mirror deflection. Then discuss the method of mathematical modeling and establish a multi-DOF micromirror static model by introducing thermal conductivity and spring rigid model which illustrates the deformation relations between the thermal conductivity and the interaction among multiple actuators. Afterwards the dynamic model is deduced by analyzing the electric and mechanical characteristics and combining the two transfer functions. At last, this model was validated by experiments.In order to reduce the actuator deviation of the structure and characteristics by fabrication process, this paper proposes a data model based control method to compensate the deviation by driving the mirror with simulation signal. To suppress the system residual vibration and reduce the settling time, in optical switch and VOA, the residual vibration is suppressed with input shaping methods in this paper. Finally, the control method of OCT scan imaging is researched and we propose a control method based on the state space algorithm to improve the mirror performance and the quality of OCT imaging.Based on the above theoretical analysis and control methods research, this paper introduces the experimental results for dimensional electrothermal micromirror in raster scanning, optical switches,VOA and the OCT imaging. The accuracy and validity of the model and the control method is verified in it. The study results for electrothermal MEMS micromirror has important value in the application of optical scanning, communications, and OCT imaging.