A fully soft generator with embedded conditioning circuitry

Abstract

This letter presents a fully soft dielectric elastomer generator (DEG) based on a capacitive kinetic-energy-harvesting mechanism. First, using the principle of a passive charge pump, a self-cycling conditioning circuit topology is proposed. Through the electrical reciprocity of a cyclically deforming DEG and another capacitor in series with it, the generated charge can be continuously supplied to the load, via a bilateral conditioning bridge. The antagonistic dual-DEG scheme not only produces a larger potential to drive more charge in the flow but also provides a basic solution to soften the whole device. A further measure is to replace the bridge diodes with special dielectric elastic switches (DESs), which can be embedded into the DEG and synchronously deformed with the latter to control the on/off state of the circuit branches. The intrinsic physical mechanism and characteristics of the change in the resistance of the DES as a function of stretch and electric fields are investigated. We tested and compared the diode-bridge and DES-bridge schemes under different electrical loads and tensile strokes. The results indicate that under certain conditions, the DES-bridge circuit can achieve comparable performance with that of a conventional scheme, which suggests that a fully soft DEG system is possible. We experimentally evaluated and discussed its reliability in practice.