Toward enhanced output performance by optimizing permittivity of capacitor medium in electret-based energy harvester

The energy harvester based on electret is an important micro self-powered source for micro-electro-mechanical system (MEMS). Here, a new novel structure for the electret-based energy harvester based on electret membrane (EM) is fabricated by serial coupling with the elastomer polydimethylsiloxane (PDMS) as the capacitor medium instead of air and springs. The relative permittivity of PDMS can be optimized by doping multi-walled carbon nanotube (CNT). The output performance becomes enhanced significantly with optimal doping. It is demonstrated that the EM can light up 100 commercial LED light, when pressed with a human finger. This work provides an intriguing design methodology for the development of the self-powered source for MEMS. • It is first report that the elastomer is used as capacitor medium in electret-based energy harvester. • The output performance of the electret-based energy harvester is markedly enhanced by optimizing relative permittivity. • A theoretical simulation model for the improving output performance of the electret-based energy harvester is proposed.