Investigation on electromagnetic microactuator and its application in micro-electro-mechanical system (MEMS)

In this paper, we presented the design, fabrication and testing of a novel bidirectional magnetic microactuator. The microactuator. is composed of an integrated planar coil and a flexible polydimethyl siloxane (PDMS) diaphragm with embedded CoNiMnP-based permanent magnet arrays. There is a 7x7 array of magnets in a unit. The PDMS. diaphragm is 2mmx2mmx41 mu m and the magnet post is 50 mu mx50 mu mx20 mu m. Computer simulation is applied to optimize the geometrical parameters. Electro-plating under external magnetic field is carried out to improve the magnetic properties of the electroplated magnet, including coercivity, remanence and magnetic energy and so on. The measured maximum coercivity, remanence and maximum magnetic energy are 26230e(208.73kA/m), 0.2T(2000G) and 10.15kJ/m(3) with the magnet post respectively. Moreover,the deflection of the PDMS membrane is proportional to the exciting current. In a case of 0.35A current, the maximum deflection of the membrane is 45 mu m. Adjusting the electroplating mold results in the variation of the electroplated structure, thus the calibration of the microactuaor. Due to the biomedical compatibility and simplicity of the fabrication, the flexible membrane-based microactuator is. potential to be used in MEMS (Micro-Electro-Mechanical System) applications, such as micropump and optical switch.