A Reusable Pseudo-Liquid-to-Solid Inertial Switch Based on Hetero-Coated Galinstan Droplets

Compared to solid-to-solid inertial switches, the devices based on liquid-to-solid contact can avoid the signal bouncing and contact wear caused by the rigid contact between the proof mass and the stationary electrode. However, most of the current liquid-to-solid inertial switches can only support one-time use. To resolve this issue, we, for the first time, present a pseudo-liquid-to-solid inertial switch that not only has a soft electronic contact but also is reusable. We utilize one graphene-coated galinstan droplet (GGD) with high conductivity as the proof mass and two polytetrafluoroethylene (PTFE)-coated galinstan droplets (PGDs) with excellent elasticity and mechanical robustness as springs to restrain the GGD. Moreover, the coated powder shell can prevent galinstan droplets from being oxidized thus enables superior performance in terms of nonstick property and high mobility. As a result, a pseudo-liquid-to-solid inertial switch with a threshold of 20 g is designed and fabricated, and it exhibits high reliability, reusability and stability with a contact time of 1 ms. In summary, this novel type of inertial switch combines the advantages and overcomes the limitations of both liquid-to-solid type and solid-to-solid type, therefore is of great potential for practical applications. [2022-0151]