We designed a nonlinear mechanical spring that counteracts the nonlinear electrostatic attraction force in the gap-closing parallel-plates actuator. What we achieved is a parallel-plates actuator in which beyond what would have been the pull-in point, voltage is maintained at a constant level even though charge is stored in – or extracted from – the deformable capacitor. In essence, this transducer responds as a rechargeable battery. In this mechanical battery electric energy is stored in elastic potential – rather than in chemical potential as in Lithium-ion rechargeable batteries.
To learn more please refer to our paper: On the Notion of a Mechanical Battery. S. Shmulevich, A. Joffe, I. (Hotzen) Grinberg and D. Elata, IEEE-JMEMS, 24(4), 1085-1091, 2015.