Modelling a combined electrostatictriboelectric flexible generator
Résumé
Soft electrostatic generators (SEG), generally made of electroactive polymers, represent an efficient way to power up devices widely used in the IoT, including smart clothes, biomechanical energy harvesters or sensors. The working principle of these generators is to use the variation of capacitance to convert mechanical energy into electrical one. Our team demonstrated that an electret can be used to replace the needed external voltage supply of these SEGs leading to an energy self-sufficient soft generator. The goal of our work is to improve the volume density of energy of our electrostatic generator by replacing the electret with a sliding-mode triboelectric function. An experimental study was conducted to better understand how this phenomenon works. This enabled to carry out a finite element modeling of the electrical power generated during the mechanical deformation (50% of strain) of our centimeter-scale generator coupling these electrostatic and triboelectric modes. A thorough optimization regarding the shape, size and materials used for this triboelectric function, has been done to achieve a targeted output power of 100uW.