Design and simulation of a MEMS based dual axis capacitive accelerometer

Abstract

Micro Electro Mechanical Systems (MEMS) based multi axis accelerometers are embedded in many modern technological applications. These sensors are widely used in smart electronics, bio-medical uses, automobiles and aeronautics. The work followed herewith is focused on designing of a 2 degree of freedom (D.O.F) MEMS based capacitive accelerometer which can be used with such vibration detection modules. The 2mm × 2mm × 100μm sensor has a working range of up to ±16g and a failure limit of 20g The movement of a proof mass which is 74.5% of the sensor area is used to generate amplified voltage signals based on the theory of capacitance using a series of capacitive comb elements mounted on the perimeter of the sensor. Process simplification is achieved with the use of a single Silicon-on-Insulation (SOI) wafer and minimum masking material. The paper contains details on structural and motion analysis performed on the design and also contains techniques which can be used for the fabrication of the sensor and electrical contacts needed for the successful implementation of the sensor into electrical circuitry.