Coaxial double helix structured fiber-based triboelectric nanogenerator for effectively harvesting mechanical energy

Harvesting energy from surrounding environment, especially from human body motions, is an effective way to provide sustainable electricity for low-power mobile and portable electronics. To be adapted to human body and its motions, we report a new fiber-based triboelectric nanogenerator (FTNG) with a coaxially double helix structure, which is appropriate for collecting mechanical energy in different forms. With a small displacement (10 mm in 1.8 Hz), this FTNG could output 850.20 mV voltage and 0.66 mA/m2 current density in lateral sliding mode, or 2.15 V voltage and 1.42 mA/m2 current density in vertical separating mode respectively. Applications onto human body are also demonstrated: output of 6 V and 600 nA (3 V and 300 nA) could be achieved when attached the FTNG on a cloth (wore on a wrist). The output of FTNG is maintained after being washed or long-time working. This FTNG is highly adaptable for human body, and has the potential to be a promising mobile and portable power supply for wearable electronic devices.