A MEMS Resonator Coupled With a Resistive Sensor for Improved Sensing and Actuation

We present a new approach to enhance the sensitivity of resistive sensors and enable threshold switching that can be used for actuation, providing a simple binary readout method. The concept is based on electrically coupling a resistive sensor with a resonant MEMS structure. Results are demonstrated for two case studies involving a resistive temperature sensor and a chemiresistive humidity sensor based on the nanocomposite material Ti3C2Tx. By tracking the resonance frequency shifts of the coupled microstructure operated near buckling, the results show significant sensitivity enhancement (more than 5-6 times) for both the temperature and humidity sensors compared to directly monitoring the resistance changes of the resistive sensors. Furthermore, results are shown for the conversion of the resonator into a tunable electrical switch based on the nonlinear pull-in phenomenon. Such a switch can simplify sensor-actuator systems and can be used as a simple binary readout method for resistive sensors.[2024-0216]