Design, simulation and optimization of sensing chip of high-g three-axis MEMS accelerometer

High-g three-axis MEMS piezoresistive accelerometer was developed in order to measure integrated accelerometer signal of the penetration process of the body of the missile of hard-target penetration weapon. A new design project of E shape diaphragm structure of central single proof mass of accelerometer was put forward. The accelerometer's structure and working principle were discussed in details. This design can measure the acceleration in three-axis directions by means of three sets of Wheatstone bridges which are disposed on the sense chip reasonably. The perfectly structural size of the sense chip was fixed by finite element analysis software. Simulation and optimization of the sense chip were implemented, by zero-order rough optimization algorithm and first-order gradient algorithm. The results indicate that the sensing chip of triaxial accelerometer have great capability of bearing over loading under 2 × 10⁵ g's peak shock acceleration, the property of high frequency response with 231 kHz, high sensivity and so forth. Finally, the prototype of triaxial accelerometer is developed. The initial tests verify that the accelerometer can fulfill high-g three-axis acceleration measurement.