Progress on wearable triboelectric nanogenerators in shapes of fiber, yarn, and textile

Textile has been known for thousands of years for its ease of use, comfort, and wear resistance, which resulted in a wide range of applications in garments and industry. More recently, textile emerges as a promising substrate for self-powered wearable power sources that are desired in wearable electronics. Important progress has been attained in the exploitation of wearable triboelectric nanogenerators (TENGs) in shapes of fiber, yarn, and textile. Along with the effective integration of other devices such as supercapacitor, lithium battery, and solar cell, their feasibility for realizing self-charging wearable systems has been proven. In this review, according to the manufacturing process of traditional textiles starting from fibers, twisting into yarns, and weaving into textiles, we summarize the progress on wearable TENGs in shapes of fiber, yarn, and textile. We explicitly discuss the design strategies, configurations, working mechanism, performances, and compare the merits of each type of TENGs. Finally, we present the perspectives, existing challenges and possible routes for future design and development of triboelectric textiles.