Static and dynamic responses of an electromagnetic bistable–bidirectional microactuator on a single silicon substrate

The aim of this paper is to characterize the static and dynamic response of a bistable–bidirectional microactuator. The bidirectional mechanism is generated from the interaction between the CoNiMnP magnet and the Au microcoil. The bistable mechanism is generated from the interaction between the CoNiMnP magnet and the soft magnetic (NiFe) base. The microactuator is entirely fabricated by surface micromachining on top of a single silicon wafer. The overall diameter ( D overall) of the microactuator is 1600 μm. The overall height ( H overall) is approximately 600 μm, including the thickness of the silicon wafer. A Laser Doppler Vibrometer (LDV) is used to test the microactuator. Test results show that the latching mechanism occurs at the membrane minimum displacement ( d min), −21 μm. An operational current ( I coil) and power ( P coil) as low as 13.9 mA and 1.39 mW are required to perform this latching mechanism. The membrane maximum displacement ( d max) is found to be 29 μm; it is achieved at I coil = 0.13 A and P coil = 130 mW. There are two different latching times observed from the experiments, a static latching time ( t latch_st) and a dynamic latching time ( t latch_dy). The t latch_st is found to be 2.5 ms. The t latch_dy varies with I coil and the smallest observed value is 0.18 ms.