Design and analysis of a new piezoelectric MEMS tilt sensor

This paper reports the design and preliminary analytical investigations of a new MEMS piezoelectric tilt sensor. The proposed tilt sensor consists of a Platinum supported beam with a central proof mass which causes the beam to deflect under gravitational loading. This static deflection generates intrinsic stress across the beam, which is a direct function of the dual-axis inclination of the sensor. A thin 0.2 μm layer of Lead Zirconate Titanate (PbZrTiO₃-PbTiO₃) deposited on the top surface of the beam where the peak stress occurs, enables the conversion of the variable stress as a function of the spatial inclination to a measurable voltage. The voltage output of the PZT layer is therefore directly proportional to the inclination of the sensor around two orthogonal axes. The feasibility of this measurement approach is validated through simulation results for a dual-axis operation range of 0 - 90°. These results further demonstrate the tunable sensitivity property of the sensor as a function of its geometry.