An Inertial Switch With Prolonged Contact Time Achieved by Dynamically Asymmetric Design

Near-zero consumption inertial switch has been widely used in various fields, such as automobiles, wearable devices, and the Internet of Things (IoT). Here, an inertial switch with excellent contact performance is proposed, which is designed by the inspiration of the intrinsic dynamic characteristics of the inertial switch and fabricated by the surface micromachining process. The inertial switch combines the lightweight movable electrode and asymmetric springs design, and the dynamic response characteristics are investigated by finite element simulation. The result indicates the movable electrode performs the rotary swing during contact-separate motion, and the contact time is positively related with the contact area between the movable electrode and fixed electrode. In the experiment, four kinds of asymmetric inertial switches are tested, and the measured thresholds are essentially comparable to the simulated thresholds, with a maximum error of less than 7%. Meanwhile, the contact time of the inertial switch is significantly prolonged without obvious signal bounce after contact, and the contact resistance remains stable after 50 shocks, demonstrating the reliability and durability of the asymmetric inertial switch. Therefore, the proposed asymmetric inertial switch can serve as an effective candidate for near-zero consumption applications in the future.