Title: Biopolymer-based active surfaces for novel tribo-electric nano generators (TENGs)

Abstract

Triboelectric Nano-Generators (TENGs) convert mechanical energy to electricity for powering small devices such as sensors or portable electronics. They harvest energy from small frequency mechanical oscillations by taking advantage of triboelectrification and electrostatic induction that takes place when the surfaces of two different dielectric materials are in alternative contact. These two active surfaces are usually made from synthetic polymeric materials such as polyamide, polytetrafluoroethylene, polyethylene terephthalate, among others. In order for TENGs to become a feasible technology for the development of novel power sources, their ecological impact must be controlled. Previous reports have shown that biopolymers could be used for the preparation of novel active surfaces of TENGs. We have tested several films made from different biopolymers such as carrageenan, starch, collagen, among others in order to assess their feasibility as triboelectric active surfaces. A TENG prototype was used to measure the output voltage and current with each of the different biopolymeric surfaces. Synthetic polymeric surfaces were also evaluated for comparison. Different combinations of biopolymer/biopolymer and biopolymer/synthetic surfaces were used. The results allowed to classify the biopolymer-based surfaces according to their electronegativity and showed different combinations of biopolymers that could be used to fabricate TENGs with good performances. The results also showed that it is possible to develop a totally biodegradable TENG.