Integration of organic/inorganic nanostructured materials in a hybrid nanogenerator enables efficacious energy harvesting via mutual performance enhancement

Abstract

Recent reports demonstrate that hybrid energy harvesting devices can efficiently convert ubiquitously available but mostly unexploited ambient energies (e.g., mechanical, chemical, thermal, solar) into usable power that can potentially support a new generation of self-powered electronic systems. In this paper, we present a hybrid organic/inorganic nanogenerator on shim substrates, which integrates both piezoelectric and triboelectric components based on inorganic p-n junction ZnO nanostructures and nanostructured organic polytetrafluoroethylene (PTFE) film, respectively. In this design, individual components can be operated independently or concurrently. Moreover, when operated concurrently, component performance is mutually enhanced, enabling more efficient conversion of mechanical energy into electrical energy in a single press-and-release cycle. When triggered with 25 Hz frequency and 1 G acceleration of external force, the piezoelectric nanogenerator (PENG) component generates a peak-to-peak output voltage of 34.8 V, which is ∼3 times higher than its output when it acts alone. Similarly, the triboelectric nanogenerator (TENG) component generates a peak-to-peak output voltage of 356 V under the same conditions, which is higher than its initial output of 280 V when acting alone. The nanogenerator unit produces an average peak output voltage of 186 V, current density of 10.02 µA/cm2, and average peak power density of 1.864 mW/cm2 when operated in the hybrid configuration. The device can even produce an average peak-to-peak voltage of ~160 V from normal hand movement when placed under a wristband fitness tracker, and ~580 V from human walking when placed within the walker's shoe. The device has been demonstrated to charge commercial capacitors up to a few volts within several seconds.