Electrostatic vibration energy harvester using multimodal-shaped springs for pacemaker application

This paper presents an innovative broadband electrostatic vibration energy harvester (eVEH) using miniaturized multimodal-shaped nonlinear springs for powering an autonomous pacemaker. The presented bioMEMS device has been designed for acceleration levels in the range of 1 g or lower, and a high frequency bandwidth in low frequency domain that allows harvesting of a real heartbeat excitation. An extensive study of the response of the device as a function of the heartbeat rate, the acceleration amplitude and its inclination with respect to the gravity field is performed. It is demonstrated that the presented device, with overall volume < 0.3 cm
³
, delivers up to 2.38 µW neat average power under real heartbeat excitation conditions with 10 m/s
²
acceleration amplitude at 116 bpm. The harvester is using the Multimodal-shaped springs, which allow to construct the mechanical nonlinearity required for sensitive wideband device in a precise way while keeping the whole system sufficiently miniaturized. The device is fabricated with dedicated clean room process on silicon-on-glass (SoG) wafer.