Design and Fabrication of a Micro Electromagnetic Actuator

A new optimized structure for micro electromagnetic actuator is introduced based on the research done before. Three-dimensional structure and new fabricate process is adopted accordingly in this improved design. The new structure can diminish the leak of magnetic circuit and increase the magnetic force. An electromagnetic micro actuator is fabricated based on the MEMS technology. The size of the micro electromagnetic actuator is about 5mm times 5mm times 0.4mm. The micro actuator consist a lower magnetic circuit, a planar exciting coil and a permalloy cantilever. Anisotropic etching, electroplating, polyimide film patterning is adopted in the fabricated process. The exciting coil has 20 turns and the resistance of the coil is about 20Omega. The initial experiments show that the permalloy cantilever displacement can reach 2mum at a current and voltage of 250mA and 5V. This electromagnetic actuator is expected to be useful in making a micro relay