Grid of hybrid nanogenerators for improving ocean wave impact energy harvesting self-powered applications

This paper describes an alternative approach for improving the output power performance for coastal wave impact energy harvesting systems, located at water-structure interfaces. This is achieved by simultaneously coupling the triboelectric and piezoelectric effects, exhibited in some materials. The use of finite element modelling, and experimental electrical characterization, enables the integration of hybrid devices into a breaking water wave generator tank. This provides a mechanism for simulating actual ocean wave conditions at low frequencies (0.7 Hz-3 Hz). Enhancements in the output performance by a factor of 2.24 and 3.21, relative to those obtained from using single triboelectric and piezoelectric nanogenerators, were achieved. This is demonstrated by evaluating the output current, voltage, transferred charge, and charging performance from a grid of up to four hybrid devices connected to capacitors of different capacitance values. Such hybrid devices were capable of powering a one-way wireless transmitter with a generated output power between 340.85 mu W and 2.57 mW and sent a signal to a receiver at different distances from 2 m to 8 m. The research shows that such an integrated device can provide a promising mechanism for developing high-performance energy harvesting mechanisms for ocean wave impact to drive self-powered systems having an average power consumption of 1-100 mW. Further, it is estimated that through the construction of large water-hybrid nanogenerator-structure interfaces, output powers of approximately 21.61 W can be generated for powering networks of self-powered sensing systems in smart large-scale applications.