Non-initial overlap bulk silicon comb-drive actuator with low-voltage and large-displacement

Two different kinds of bulk-Si comb-drive actuators are designed in this work: initial overlap comb-drive actuator and non-initial overlap comb-drive actuator. They are fabricated by a simple post-CMOS bulk micromachining process. A cascade folded beam is designed to achieve large displacement at low driving voltages. And non-initial overlap and unequal wide comb fingers are used to reduce the side instability and improve the pull-in voltage. The measurement results show that the non-initial overlap comb-drive actuator improves the pull-in voltage by 73.3% than the initial overlap comb-drive actuator, and the maximum displacement of the non-initial overlap actuator is larger by 78.9% than that of the initial overlap actuator.