Nanopillar-array architectured PDMS-based triboelectric nanogenerator integrated with a windmill model for effective wind energy harvesting

Triboelectric nanogenerator (TENG) is an up-and-coming technology that functions based on the triboelectrification and electrostatic induction to generate the electricity from various mechanical energy sources. However, the practical applications still demand a significant improvement of the TENG output performance, so the optimization of key factors such as triboelectric material selectivity, nanostructure-like morphology, and surface contact area is very crucial. Here, we reported a TENG based on nanopillar-array architectured polydimethylsiloxane (NpA-PDMS) layers with simple and cost-effective fabrication process, high output performance, and long-term stability. We mainly focused on improving the output performance of TENG by optimizing the structural dimensions of nanopillar architectures (NpAs) distributed on the surface of PDMS. The effect of output performance of TENG by varying the period and diameter of NpAs on the surface of PDMS was theoretically and experimentally investigated. For theoretical study, we considered the NpA-PDMS as a viscoelastic material. From this simulation, we calculated the contact stress for NpA-PDMS layers and compared the behaviors by considering the contact area and stress together (i.e., the product of contact area and stress, called as a contact force). Surprisingly, the calculated results were well matched with the experimental data. And, an optimal NpA-PDMS with the period and diameter of 125 nm and 60 nm, respectively, was formed. Thus, the TENG with the optimal NpA-PDMS exhibited the open-circuit voltage (V-OC) and short-circuit current (I-SC) values of similar to 568 V and similar to 25.6 mu A, respectively, under 10 N of pushing force and 5 Hz of pushing frequency. Additionally, the enduringness test of the TENG device was also conducted to confirm its mechanical stability and durability. Finally, for a real application, the optimized TENG device was incorporated with a windmill system to effectively harvest the wind energy available in indoor and outdoor environments. This windmill system effectively harvested the wind energy, exhibiting the V-OC and I-SC values of similar to 200 V and similar to 24 mu A, respectively, at the wind speed of 14-15 m/s.