Triboelectric nanogenerators (TENGs) are widely applied to the self-powered devices and force sensors. TENGs consists of the electrode-layer frequently made of high-cost conductors (Ag, Au, ITO) and the tribo-layer of rigid negative-triboelectricity fluoropolymers (PTFE, FEP). The surface morpholoy is studied for enhancing performance.

Here, we propose a high-performance Al/PDMS-TENG with a novel complex morphology of overlapped deep two-height microneedles (OL-DTH-MN) fabricated by the integrated process of low-cost CO2 laser ablation and PDMS casting for the self-powered devices and high-sensitivity force/pressure sensor. The high open-circuit voltage and short-circuit current of OL-DTH-MN-TENG are 167 V and 129.3 μA. Also, the sensitivity of force/pressure sensor of OL-DTH-MN-TENG is very high 1.03 V N-1 and about 3.11 V kPa-1 at an area of 30 cm2 that is much higher than the sensitivity of about 0.18~0.414 V N-1 and 0.013~0.29 V kPa-1 of conventional TENG sensors. Meanwhile, the high-performance OL-DTH-MN-TENG not only exhibits the energy storage capability charging a 0.1 μF capacitor to 2.75 V at 1.19 s, to maximum 3.22 V but also activates various self-powered devices including lighting on colorful 226 LEDs connected in series, the "2020-ME-NCKU" advertising board, calculator and temperature sensor. Numerical simulation is also performed to support the experiments.

https://onlinelibrary.wiley.com/doi/10.1002/smll.202001209