Flexible single-electrode triboelectric nanogenerator with MWCNT/PDMS composite film for environmental energy harvesting and human motion monitoring

With the rapid development of wearable electronic devices, modern portable energy sources pay more attention to lightweight, low cost, high flexibility and high efficiency. This paper proposed a flexible single-electrode triboelectric nanogenerator (S-TENG) composed of multi-walled carbon nanotube (MWCNT)/polydimethylsiloxane (PDMS) film. The S-TENG has the advantages of high flexibility, high hydrophobicity, light weight, low cost, and high output efficiency. The peak-to-peak open circuit voltage can reach 435 V and the maximum short-circuit current density is 13 μA·cm−2 under continuous pressing. When the external load is 40 MΩ, the maximum output power density is 3.7 mW·cm−2. The S-TENG can not only harvest the mechanical energy generated by biological movement, but also can be used as a sensor to effectively detect human movement and handwriting traces. In addition, a 4 × 4 sensor array and a wireless transmission system were constructed to realize multi-point distributed detection and wireless transmission of portable smart terminals. The S-TENG can harvest energy from falling water droplets, uninterrupted water flow, wind and percussion sounds, which demonstrates its broad application prospects in the field of flexible wearables.Graphical abstract