Sliding-Triboelectric Nanogenerators Based on In-Plane\nCharge-Separation Mechanism

Abstract

Aiming at harvesting ambient mechanical\nenergy for self-powered\nsystems, triboelectric nanogenerators (TENGs) have been recently developed\nas a highly efficient, cost-effective and robust approach to generate\nelectricity from mechanical movements and vibrations on the basis\nof the coupling between triboelectrification and electrostatic induction.\nHowever, all of the previously demonstrated TENGs are based on vertical\nseparation of triboelectric-charged planes, which requires sophisticated\ndevice structures to ensure enough resilience for the charge separation,\notherwise there is no output current. In this paper, we demonstrated\na newly designed TENG based on an in-plane charge separation process\nusing the relative sliding between two contacting surfaces. Using\nPolyamide 6,6 (Nylon) and polytetrafluoroethylene (PTFE) films with\nsurface etched nanowires, the two polymers at the opposite ends of\nthe triboelectric series, the newly invented TENG produces an open-circuit\nvoltage up to ∼1300 V and a short-circuit current density of\n4.1 mA/m² with a peak power density of 5.3 W/m², which can be used as a direct power source for instantaneously\ndriving hundreds of serially connected light-emitting diodes (LEDs).\nThe working principle and the relationships between electrical outputs\nand the sliding motion are fully elaborated and systematically studied,\nproviding a new mode of TENGs with diverse applications. Compared\nto the existing vertical-touching based TENGs, this planar-sliding\nTENG has a high efficiency, easy fabrication, and suitability for\nmany types of mechanical triggering. Furthermore, with the relationship\nbetween the electrical output and the sliding motion being calibrated,\nthe sliding-based TENG could potentially be used as a self-powered\ndisplacement/speed/acceleration sensor.