Design and Simulation of an Electrostatic Energy Harvester for Biomedical Implants

Abstract

This paper presents the design of an electrostatic MEMS energy harvester for medical implant application. It examines solutions for constraining the motion of the mobile part in one direction and proposes an innovative spring architecture. Indeed, constraining the mobile part motion is essential to avoid undesired contact between comb electrodes. It is particularly important in environments in which mechanical vibrations result from complex combination of rotations and translations. The objective of the considered device is to power the next generation of leadless pacemakers using mechanical energy generated by heartbeat motion. Such solution would dramatically increase the lifetime of implants and would be very beneficial for the patients by reducing the number of replacement surgical operations. Numerical simulations based on analytical modelling and acceleration signal mimicking heartbeat motion enabled to analyze the system response in various condition, showing the interest and benefits of the proposed approach.

Microfabrication and Characterisation of an Electrostatic MEMS Energy Harvester for Biomedical Applications

“…This work is the continuation of the previous work presented in [11]. We present herein an improved design which enabled to reduce the mechanical stress in the silicon springs compared to the asymmetrical former design.…”

“…In order to avoid sticking on one stopper due to gravity, we choose a natural frequency of 57Hz to have an offset of 76.48𝜇𝑚 when gravity field is parallel to the direction of motion of the mobile part. This offset forbids the capacitor combs to engage and disengage completely, this causes the output power to be lower compared to the case when gravity field is perpendicular to the direction of motion [11].…”

“…The double beams constraint the movements on the in plane perpendicular direction of movement by avoiding rotations of the spring arm supports. This geometry allows to distribute better the weight of the mass compared to the guiding beam design in [11].…”

A Novel Silicon on Glass Electrostatic MEMS for Energy Harvesting in Leadless Pacemakers

“…The so-called Guiding Beam structure we proposed in [6] was designed to fit inside the LPM, i.e. the MEMS device should fit in a cylindrical cavity with 6 mmdiameter and 2 mm-length.…”

“…In the present work, we report the fabrication and characterization of the MEMS energy harvester for LPMs designed in [6].…”