Structural design, analysis and DOE of MEMS-based capacitive accelerometer for automotive airbag application

Accelerometers are one of the simplest and most important applications of Micro-Electromechanical Systems (MEMS). This paper deals with the design, analysis and Design of Experiments (DOE) of a MEMS-based capacitive accelerometer for automotive applications. The key design parameters to be considered while designing an accelerometer are the sensitivity and the bandwidth of operation. The present work focuses on the design and improvement of an accelerometer to ensure that it operates for a larger bandwidth without compromising on the sensitivity. The structural parameters, overall dimensions and size of the accelerometer are first identified. Subsequently, a parametric analysis is performed using $${2}^{k}$$ Design of Experiments for various g values from 5 to 50 g totalling 40 runs. Depending on the level of influence, these structural parameters are then modified for an improved accelerometer design. Later, a sensitivity analysis is performed. It was seen that the improved design performed better than the rest. A Modal analysis was also performed to determine the resonant/natural frequencies and the mode shapes. It was found that the presented design is safe to operate. This method of approach would help in arriving at a better accelerometer for the desired application.