Whole garment knitting-enabled direct current triboelectric nanogenerators

Wearable electronics require compact, reliable, and sustainable power sources. Fabric-based triboelectric nanogenerators (TENGs) offer a promising solution by combining energy harvesting with the inherent softness and breathability of textiles. However, conventional functionalization methods, such as surface coatings or multilayer structures, inevitably diminish these essential properties. To address this issue, we developed a knitted fabric-based direct current triboelectric nanogenerator (KF DC-TENG) using whole-garment knitting technology and the air breakdown effect. This design allows direct application without complex post-processing and eliminates the need for external rectification. A single unit of KF DC-TENG (8 × 2.5 cm2), after structural optimization, is capable of lighting 744 series-connected Light Emitting Diodes (LEDs) when manually rubbed against polytetrafluoroethylene (PTFE) fabric. Integration with a low-cost power management circuit (PMC, ~1.5 CNY) further enhances the output power by 290 times. As a result, 17 s of friction can power an electronic watch for up to 8 min. Moreover, continuous sliding can sustain a 1.5 W LED without noticeable flickering. This work presents the first demonstration of integrating whole-garment knitting technology with DC-TENGs, offering a scalable and cost-effective strategy for self-powered wearable electronics.