Multi-layered disk triboelectric nanogenerator for harvesting hydropower

New technologies that can scavenge ambient environmental energy have attracted increasing interest in the past decades. Recently, triboelectric nanogenerator (TENG) has been demonstrated as a powerful approach for harvesting various forms of mechanical energies. In this work, a newly designed TENG is demonstrated by coaxially integrating multiple layers disk TENGs into a whole system, which transforms the fluid flow into rotation motion of multiple layers disks and generates a multiplied electrical output. To achieve the effective structural integration and output multiplication, a D-shape shaft is adopted to facilitate the synchronized relative rotation of all the segmentally-structured disk layers and light weight and low stiffness springs are employed to ensure the intimate contact of the tribo-surfaces. With the above design, the nanogenerator delivers an open-circuit voltage up to similar to 470 V and a short-circuit current density of 90.6 mA/m(2), corresponding to an instantaneous maximum power density of 42.6 W/m(2) (2.68 kW/m(3)) at a rotation speed of 1000 rpm. By combining the TENG with a water turbine, the device can be effectively driven by a water flow from a common household faucet. This technology represents an important advance of TENGs toward practical applications and shows great potential in hydroelectric power and wind power industries. (C) 2014 Elsevier Ltd. All rights reserved.