Triboelectrically Self-powered, Structural Carbon-fiber-reinforced Composites

Abstract

As fossil fuel depletion is accelerating and energy saving is becoming increasingly critical, intensive efforts are being made to develop environmentally friendly, ultra-lightweight materials for applications in weight-sensitive structures, such as automobiles, aircraft, ships and civil structures. Carbon-fiber-reinforced plastic (CFRP), which is an ultra-lightweight material with a density only a fraction of steel, is well suited for structural applications, where a high strength-to-weight ratio is demanded. Here, we present a proof-of-concept study and demonstration of multi-functional CFRPs that serve as the “structural electrodes” – owing to the high electrical conductivity of carbon fibers - in a triboelectric generator system. If a dielectric material is deposited on the CFRP electrodes and rubbed against one another, the surfaces of the two dielectrics become oppositely charged, and the change in the gap between the two dielectrics induces electrostatic induction. This leads to the accumulation of negative charges along the carbon fiber electrode, thus, generating the electrical energy. Harvesting energy from friction allows high efficiency at low frequency, affordability and low weight due to relatively simple mechanisms and implementation, and this adds a great value and functionality to lightweight, structural CFRPs. The self-powered CFRPs transform the abandoned mechanical energy into usable electrical energy, which will find numerous applications where repetitive loading-unloading is applied, including power-generating speed bumps, roads, railways, doormats, and vibrating structures.