Why is surface texturing employed in TENG fabrication?

Surface texturing is employed in TENG fabrication to enhance the effective contact area between the triboelectric materials. The actual area of contact between two surfaces is often much smaller than the apparent or geometric contact area, especially when the surfaces are smooth. Surface texturing, which involves creating micro- or nano-scale patterns or roughness on the material surface, increases the real contact area. This leads to a greater number of contact points where charge transfer can occur during triboelectrification. By increasing the real contact area, surface texturing facilitates more efficient charge transfer, resulting in higher charge density on the triboelectric surfaces and consequently, improved TENG output performance. The texturing can be achieved through various methods like etching, laser ablation, or deposition of patterned thin films. For example, creating a micro-pyramid structure on a PDMS (polydimethylsiloxane) film will significantly increase its effective contact area when it comes into contact with another material, like nylon, compared to a smooth PDMS film, leading to more triboelectric charge generation.