M-X Li, X. Chen, X. Pan, J-S. Kang
Beijing Institute Technology, China
pp. 125 - 129
Keywords: electrostatic imaging, MEMS system, finite element analysis
The electrostatic imaging system obtains the contour profile of charged target by sensing the electrostatic field around. MEMS technology has the characteristic of microelectronic integration and miniaturization. In this paper, an electrostatic imaging system is designed based on MEMS technology, improving the imaging resolution and reducing the volume of the electrostatic imaging system simultaneously. Firstly, this paper proposes the design scheme of electrostatic imaging system, where each imaging unit is compose of conditioning circuit, shielding cylinder and the electrode structure of relative vibration of shielding electrode and induction electrode. Based on different vibration modes of the shield electrode, we propose two kinds of design schemes, which are vertical vibration type and transverse vibration type. Furthermore, the existence of grounding shielding cylinder makes only the electric-field lines generated by target’s partial parts in front of sensor enter the sensor, and the electric-field lines are truncated in other directions, which reflects directed detection in part. Secondly, the structure model of the two kinds of imaging unit was built and the direction and sensitivity of each unit are analyzed by using MAXWELL. The analysis result shows that the transverse vibration type has higher sensitivity rate, so we choose this vibration type as our final design of electrostatic imaging MEMS unit. Finally, planar network type of imaging array is laid by using the directional electrostatic imaging MEMS sensor as the basic unit in square adjacent. A cross-shaped charged body is chosen as the imaging target to simulate the imaging effect of the imaging system. An image processing is designed by using image denoising and enhancement method. The simulation result shows that the imaging array composed by the electrostatic imaging MEMS unit can effectively fulfill the function of imaging the target. Compared with other imaging methods, electrostatic imaging has the advantages of good concealment, anti-interference, anti-stealth, and is valuable to research. In this paper, directional electrostatic imaging system is designed based on MEMS technology. Then we simulated the imaging effect of the imaging system, which showed that our design scheme was reasonable. It can be utilized to detect charged target, security monitoring or other fields and has a broad application prospect.