High‐Performance Al/PDMS TENG with Novel Complex Morphology of Two‐Height Microneedles Array for High‐Sensitivity Force‐Sensor and Self‐Powered Application

Abstract Triboelectric nanogenerators (TENGs) are widely applied to self‐powered devices and force sensors. TENGs consist 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, a high‐performance Al/PDMS‐TENG is proposed with a complex morphology of overlapped deep two‐height microneedles (OL‐DTH‐MN) fabricated by the integrated process of low‐cost CO 2 laser ablation and PDMS casting for self‐powered devices and high‐sensitivity force/pressure sensors. The high open‐circuit voltage and short‐circuit current of the OL‐DTH‐MN‐TENG are 167 V and 129.3 µA. Also, the sensitivity of the force/pressure sensor of the OL‐DTH‐MN‐TENG is very high, 1.03 V N −1 and about 3.11 V kPa −1 , at an area of 30 cm 2 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 of 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 colorful 226 LEDs connected in series, the “2020‐ME‐NCKU” advertising board, a calculator and a temperature sensor. Numerical simulation is also performed to support the experiments.