Machine-washable and breathable pressure sensors based on triboelectric nanogenerators enabled by textile technologies

Utilization of textile's triboelectric effect to realize the perception of pressure is of great interest for self-powered wearable electronics that integrate seamlessly with smart fabrics. However, the challenges associated with rational material/device designs based on conventional textile structures and the lack of understanding of the mechanical circumstances experienced by textile devices hamper the further advancement of this technology. Here, textile pressure sensors based on triboelectric nanogenerators (TENGs) with machine washability and excellent breathability are manufactured by using machines to interlace robust Cu-coated polyacrylonitrile (Cu-PAN) yarns and parylene coated Cu-PAN (parylene-Cu-PAN) yarns via multiple textile industry compatible technologies for the first time, simultaneously achieving devices with stitched, woven, and knitted structures. TENG-based pressure sensors with different textile structures are investigated under as-fabricated conditions and after machine washing, and a relation is proposed between textile structure and the key characteristics of the sensors. The material/device designs, mechanical circumstances, manufacturing methods, etc., will affect the sensitivity, linearity, saturation trend and washability of the obtained sensors. Finally, a smart textile glove with stitched pressure sensors is made to demonstrate grip posture detection in various circumstances.