Near-zero stiffness MEMS accelerometer utilizing electrothermal buckling in a closed loop configuration

This study introduces a novel closed-loop near-zero stiffness micro-electro-mechanical system (MEMS) accelerometer. It achieves high, adjustable sensitivity by tuning the buckling behavior of electrothermal microbeams. A closed-loop force feedback control system is implemented for the accelerometer, effectively enhancing its linearity, dynamic range, bandwidth, and operational stability. The control parameters are optimized through system-level modeling. The experiment demonstrates that the closed-loop system enhances linearity and bandwidth by 41.5% and 106%, respectively, compared to the open-loop system. Furthermore, across a temperature range of 20 °C–60 °C, the closed-loop system decreases output drift by 36%, compared to the open-loop system. This closed-loop control method can be widely applied to various near-zero stiffness MEMS accelerometers (e.g. those with mechanical anti-spring configurations). This research lays the groundwork for future advancements in high-performance sensing technologies.