Haircell-inspired capacitive accelerometer with both high sensitivity and broad dynamic range

This paper reports the preliminary development of a capacitive accelerometer that possesses high sensitivity and broad dynamic range simultaneously. Our idea of improving these two conflicting requirements is to incorporate positive and negative feedbacks into the system, inspired by the operation mechanisms of the inner ear hair cells. The positive feedback selectively amplifies small inputs but stops functioning for large inputs, realizing the bio-inspired compressive nonlinearity. On the other hand, negative feedback is implemented to reduce the DC drift, which also helps to achieve a high sensitivity by maintaining the operating point at the origin. To prove the concept, a capacitive accelerometer with multiple electrostatic comb drives was designed, fabricated and preliminarily tested. The results show enhanced sensitivity and reduced DC drift by applying actuation voltages to the comb drives, hence demonstrating the feasibility of the haircell-inspired accelerometer.