Force feedback control is a principle which has been used to improve the performance of sensors for a long time. In this project, we apply force feedback control to the piezoelectric corrugated membrane-based microphone in Figure 1. [1, 2] An impinging soundwave excerts a force on the membrane, which leads to deflection and induces a sensor voltage. The force feedback-based microphone has an actuator that also excerts a force on the membrane and reduces the sensor signal. The sensor signal is amplified and fed back to the actuator to keep the membrane at a constant position. The output of the sensor system is the actuator signal. Force feedback has several advantages: 

• The linearity and precision of the sensor system depend only on the calibration of the actuator. Since the feedback drives the membrane to its center position the linearity of the sensor is not so important. [3]

• Force feedback can even resolve design compromises. The bandwidth of a microphone inherently conflicts with its sensitivity. The bandwidth of a sensor with force feedback however depends primarily on the tightness of the feedback loop. This allows to enhance the bandwith of a very sensitive sensor by designing the control loop accordingly.

To realize the concept, we rely on design optimization using FEM-simulation paired with evolutionary algorithms, and physical compact modelling supported by electroacoustical and optical device characterization.