Sliding-Triboelectric Nanogenerators Based on In-Plane Charge-Separation Mechanism

TLDR

Triboelectric nanogenerators harvest ambient mechanical energy, but existing designs rely on vertical charge separation that demands complex structures to maintain output. This study introduces a sliding triboelectric nanogenerator that uses in‑plane charge separation through relative sliding between two contacting surfaces. The device operates by generating electricity as the two surfaces slide, producing an open‑circuit voltage of ~1300 V, a short‑circuit current density of 4.1 mA m⁻², and a peak power density of 5.3 W m⁻², sufficient to drive hundreds of LEDs. Compared to vertical‑touching TENGs, the planar‑sliding design delivers higher efficiency, easier fabrication, and can serve as a self‑powered displacement, speed, or acceleration sensor.

Abstract

Aiming at harvesting ambient mechanical energy for self-powered systems, triboelectric nanogenerators (TENGs) have been recently developed as a highly efficient, cost-effective and robust approach to generate electricity from mechanical movements and vibrations on the basis of the coupling between triboelectrification and electrostatic induction. However, all of the previously demonstrated TENGs are based on vertical separation of triboelectric-charged planes, which requires sophisticated device structures to ensure enough resilience for the charge separation, otherwise there is no output current. In this paper, we demonstrated a newly designed TENG based on an in-plane charge separation process using the relative sliding between two contacting surfaces. Using Polyamide 6,6 (Nylon) and polytetrafluoroethylene (PTFE) films with surface etched nanowires, the two polymers at the opposite ends of the triboelectric series, the newly invented TENG produces an open-circuit voltage up to ∼1300 V and a short-circuit current density of 4.1 mA/m2 with a peak power density of 5.3 W/m2, which can be used as a direct power source for instantaneously driving hundreds of serially connected light-emitting diodes (LEDs). The working principle and the relationships between electrical outputs and the sliding motion are fully elaborated and systematically studied, providing a new mode of TENGs with diverse applications. Compared to the existing vertical-touching based TENGs, this planar-sliding TENG has a high efficiency, easy fabrication, and suitability for many types of mechanical triggering. Furthermore, with the relationship between the electrical output and the sliding motion being calibrated, the sliding-based TENG could potentially be used as a self-powered displacement/speed/acceleration sensor.