Textile-based triboelectric nanogenerators (TENGs) have received considerable attention for wearable applications owing to their significant advantages, such as flexibility, lightness, and breathability. Recently, several studies based on the modification of friction surfaces for improving the triboelectric output performance have been reported. However, previously reported methods require complicated fabrication processes and may deteriorate the intrinsic properties of a textile. Herein, we present a wearable TENG utilizing a textile composed of pile-embroidered (rough-textured) fibers as a contact surface. The deformability of the fibers originating from the suspended structure provides a large contact area that can participate in triboelectrification. This significantly increases charge density induced on the surface in response to a compressive force, resulting in a high output voltage of 113 V. The TENG also exhibits a high output power, which is 24 times higher than that of the TENG based on satin-embroidered (flat-textured) fibers. More importantly, owing to the conventional textile manufacturing process based on three-dimensional embroidery, the fabrication of our TENG is significantly simpler and more cost-effective than previously reported techniques. Experimental demonstrations as a wearable energy harvester highlight the utility of the TENG for generating electricity from various human motions. Based on ease of manufacturing and high output performance, the proposed harvester is a promising candidate as a low-cost power source for next-generation electronics, such as Internet of Things devices and self-powered smart clothing.

We present a triboelectric energy harvester fabricated with a simple electrospinning process of polyvinylidene fluoride/polyurethane polymers on conductive fabric. This electrospinning process provides higher electrical power output and hydrophobicity driven humidity resistance compared to flat polymer energy harvesters. By using conductive fabric as collector and electrode, the device could retain air permeability and flexibility. The triboelectric energy harvester exhibits a high open-circuit voltage of 45.1 V (at a compressive contact force of 20 N and relative humidity (RH) of 20%), humidity resistance (maintains about 40% of the open-circuit voltage at RH of 80%) and air permeability without deteriorating the air permeability of the fabric. Its durability was tested and shows no significant degradation of electrical output throughout 324,000 cycles of operation. This work suggests an approach for human energy harvesting in textile form with electrospun nanofibers as the contact surfaces of a triboelectric energy harvester.

While there have been remarkable improvements in the fabrication of suspended nanowires, placing a single nanowire at the desired location remains to be a challenging task. In this study, a simple method is proposed to fabricate suspended nanowires at desired locations using an electrospinning process and a designed microstructure. Using electrospun polymer fibers on the designed microstructure as a sacrificial template, various materials are deposited on it, and the electrospun fibers are selectively removed, leaving only nanowires of the deposited material. After the polymer fibers are removed, the remaining metal fibers agglomerate into a single nanowire. Throughout this process, including the removal of the polymer fibers, the samples are not exposed to high temperatures or chemicals, thereby allowing the formation of nanowires without oxidation or contamination. The diameter of the nanowire can be controlled in the electrospinning process, and a suspended Pd nanowire with a minimum diameter of 100 nm is fabricated. Additionally, a suspended single Pd nanowire-based H ₂ gas sensor fabricated using the proposed process exhibits a highly sensitive response to H ₂ gas.