A MEMS resonant tilt sensor with high sensitivity maintained in the whole 360° measurement range

In this paper, a MEMS tilt sensor with high sensitivity maintained in the full range is designed and evaluated by open-loop measurement. The sensor contains a hexagon proof mass, micro-lever force amplifiers and three double-ended tuning fork (DETF) resonant strain gauges, converting variations of gravity to resonant frequency shift. The structure of the sensor is analyzed using finite element simulation, and then fabricated through a commercial silicon-on-insulator (SOI)-MEMS foundry process. The measured sensitivity can reach at least 858.6Hz/90° in the full range from 0°to 360°, which verifies the design concept. Based on this preliminary work, the sensitivity of re-designed tilt sensor is expected to reach 1700Hz/90° after an optimization.