Highly Tunable, Low-g MEMS Inertial Switch for Power-Efficient IoT Wake-Up Functions

This paper presents a highly tunable low-g microelectromechanical systems (MEMS) inertial switch. The switch is specifically designed as a low-power wake-up device for Internet-of-Things (IoT) applications. The designed inertial switch is sensitive to in-plane accelerations in all directions (omnidirectional). The proposed inertial switch has been modeled and simulated both analytically and using finite element analysis techniques. The switch prototype has been fabricated through an in-house optimized silicon-on-insulator (SOI) wafer process, which allows patterning on both the device and handle silicon layers. The fabricated inertial switch was experimentally tested using a closed-loop shaker system to measure acceleration thresholds and a tilt stage for electrical resistance measurements. This inertial switch demonstrates the ability to tune the acceleration threshold in a wide range of 0.25 g to 2 g. This promising inertial sensor holds a significant potential for applications requiring a high dynamic range for acceleration threshold detection, such as mechanical wake-up functions in IoT devices.