Flexible, durable, and washable triboelectric yarn and embroidery for self-powered sensing and human-machine interaction

The novel combination of textiles and triboelectric nanogenerators (TENGs) successfully achieves self-powered wearable electronics and sensors. However, the fabrication of Textile-based TENGs remains a great challenge due to complex fabrication processes, low production speed, high cost, poor electromechanical properties, and limited design capacities. Here, we reported a new route to develop Textile-based TENGs with a facile, low-cost, and scalable embroidery technique. 5-ply ultrathin enameled copper wires, low-cost commercial materials, were utilized as embroidery materials with dual functions of triboelectric layers and electrodes in the Textile-based TENGs. A single enameled copper wire with a diameter of 0.1 mm and a length of 30 cm can produce over 60 V of open-circuit voltage and 0.45 µA of short circuit current when in contact with polytetrafluoroethylene (PTFE) fabric at the frequency of 1.2 Hz and the peak value of contact force of 70 N. Moreover, the triboelectric performance of enameled copper wire after plasma treatment can be better than that without plasma treatment, such as the maximum instantaneous power density can reach 245 μW/m which is ∼ 1.5 times as much as the untreated wire. These novel embroidery TENGs possess outstanding triboelectric performance and super design capacities. A 5 × 5 cm² embroidery sample can generate an open-circuit voltage of 300 V and a short circuit current of 8 μA under similar contact conditions. The wearable triboelectric embroidery can be employed in different parts of the wear. A self-powered, fully fabric-based numeric keypad was designed based on triboelectric embroidery to serve as a human-machine interface, showing good energy harvesting and signal collection capabilities. Therefore, this study opens a new generic design paradigm for textile-based TENGs that are applicable for next-generation smart wearable devices.