Fabrication of Vertical MEMS Actuator with Hollow Square Electrode for SPR Sensing Applications

Abstract

In this study, an electrostatically driven vertical MEMS actuator was designed using a hollow square electrode. To attain vertical actuation, a hollow square-shaped electrode was designed on the glass substrate. The silicon proof mass, containing a step, was utilized to realize analogue actuation without pull-in. The vertical MEMS actuator was fabricated using the SiOG (Silicon on Glass) process and the total actuator size was 8.3 mm × 8.3 mm. The fabricated proof mass was freestanding due to eight serpentine springs with 30 μm width. The vertical movement of the MEMS actuator was successfully controlled electrostatically. The measured vertical movement was 5.6 µm for a voltage of 40 V, applied between the top silicon structure and the hollow square electrode. The results shown here confirm that the proposed MEMS actuator was able to control the vertical displacement using an applied voltage.

A Novel MEMS Actuator Driven with a Low DC Voltage

“…Several studies have been conducted over two decades to solve this problem, (14)(15)(16)(17)(18)(19)(20)(21)(22)(23) however none of them has achieved a displacement larger than 6 μm at a dc driving voltage typically used in MCU boards. We have focused on this matter and proposed a revolutionary structure that overthrows the conventional structures of electrostatic microactuators, which were considered to be unable to drive large amounts of displacement.…”