Coaxial tribonegative yarn TENG with aromatic polyimide as charge entrapment layer for real-time edge ball assessment in cricket sports

Abstract

Energy harvesting yarns working on triboelectric effect by converting mechanical energy into electricity for running wearable electronics as well as operating as self-powered sensors, are superb choices for wearable electronics of current and future generations. However, current yarn-based triboelectric nanogenerators (TENGs) designed through electrospinning process are limited in achieving higher outputs, comfort, mechanical strength, washability, and industrial scalability. In this study, we introduce a flexible and durable tribonegative yarn TENG (TNY) with an electrospun polyimide (PI) intermediate charge trapping layer between the electrode and electrospun superhydrophobic polyvinylidene difluoride (PVDF)/Poly(dimethylsiloxane) (PDMS). In this coaxial arrangement, the PI charge entrapment layer enabled the TNY to exhibit an output voltage of 14 V in a 2.5 cm length, compared to only 8 V for TNY without PI layer. The TNY can be successfully woven and knitted into electronic textiles (E-Textiles), with their outputs compared based on various knitted and woven patterns. The E-Textile maintained considerable outputs after washing and withstood 5000 Martindale abrasion cycles. The superhydrophobic behavior also enabled TNY to harvest water energy from a running tap. We demonstrated the potential of these E-Textiles for edge ball sensing in cricket sports in real-time by leveraging the benefits of triboelectrification, thereby avoiding the need for complex camera setups and sound systems for judging ball movements at ± 140 km/hr in real sports. We also employed E-Textiles for smart switch functions, which can be beneficial in smart systems. This study demonstrates the improved performance of yarn-based TENGs and further extends the applications of TENGs in sports analysis. It provides a facile and high-efficiency approach for designing triboelectric sensors, offering a cost-effective alternative to complex and expensive sports equipment.