Scavenging energy with dielectric polymers: Improvements and next challenges
Résumé
To ensure the autonomy of various sensors, a promising alternative to batteries is to scavenge mechanical ambient energy. In many applications, such as e-textiles, boat sails, shock absorbers or door hinges, the transducers must be deformable, adaptable and modular, i.e. a transducer made of dielectric polymers. Indeed, these polymers are economical, light, flexible and resistant. They have a fast response time, are efficient and deform significantly. Nevertheless, there are passive materials requiring the realization of energetic cycles to convert mechanical energy into electrical. Cycles at constant charge or constant voltage must be realized and an exterior high poling voltage (kV) is needed. Thus, the improvement of dielectric generator will requires the development of performing power management as well as the improvement of the dielectric polymers. Here, we present a new design of scavenger using electrets for poling the dielectric polymer which is a first step toward a fully autonomous system. Our scavenger is composed of commercial dielectric polymer (3M VHB 4910) with patterned Teflon electrets developing a potential of -300V, and patterned grease electrodes. This solution is analytically modelled and simulated. The performances are compared with those obtained with a constant charge cycle. The power management of all these structures are explained and compared in term of efficiency and useful output energy. Fabrication of the new scavengers is under development.