Hybrid triboelectric nanogenerator for harvesting water wave energy and as a self-powered distress signal emitter

In this paper, a hybrid triboelectric nanogenerator (TENG) has been developed for simultaneously harvesting the electrostatic energy and mechanical impact energy from water wave. It is comprised of two parts: an interfacial electrification enabled TENG (IE-TENG) and an impact-TENG. The IE-TENG, composed of a fluorinated ethylene propylene thin film and an array of electrodes underneath, is used to harvest electrostatic energy arising from the water-solid interface. The impact-TENG, constructed with nanostructured polytetrafluoroethylene (PTFE) thin films and elastic wavy electrodes, is used to scavenge the mechanical impact energy from water wave. Under water waves propagating at a speed of 0.5 m/s, the short-circuit current of the IE-TENG and impact-TENG can reach 5.1 mu A and 4.3 mu A, respectively, which is able to drive nearly 50 LEDs simultaneously. Considering that natural water bodies may contain minerals and salt, the influence of NaCl concentration on the electric output of device has been investigated. Moreover, the hybrid TENG was developed as a self-powered distress signals emitter that may be used for life saving in water landing or swimming in evening. Considering the scalability of this technology, this work demonstrates the great potential of TENG in areas of hydropower harvesting, environmental monitoring and maritime search and rescue. (C) 2014 Elsevier Ltd. All rights reserved.