Design and Implementation of a Novel Membrane-Island Structured MEMS Accelerometer With an Ultra-High Range

Abstract

Antioverload high-range accelerometer is playing an increasingly important role in the field of hard target penetration testing, and the demand of higher accuracy and higher range accelerometers is growing consequently. Therefore, a novel accelerometer with a new structure of membrane island is proposed in this article, while the measurement range is significantly improved to 200 000 g. The design is mainly based on the finite-element method. In general, the membrane-island structured piezoresistive accelerometer is formed of a four-clamped membrane that carries a piezoresistor at the four ends. The four piezoresistors form a Wheatstone bridge. Then, based on the Timoshenko plate and shell theory, a mathematical stiffness model of the four-clamped membrane is established. The detailed parameters of the sensor are carried out by the finite-element analysis (FEA) and optimization, and it has a maximum stress of 26.8 MPa and a maximum displacement of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.208~\mu \text{m}$ </tex-math></inline-formula> when applying an input acceleration of 200 000 g. Finally, the sensitivity test, antioverload test, and dynamic test of three membrane-island structured prototypes are carried out, and their sensitivities are 0.579, 0.505, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.532~\mu \text{V}$ </tex-math></inline-formula> /g, respectively; the passband with 5% dynamic error is 14.9, 16.5, and 15.8 kHz, respectively. The accelerometer has an antioverload capability of 250 000 g, which is verified by the Hopkinson bar. The test results show that this membrane-island structured accelerometer has both good antioverload capability and high accuracy.