Programmable 3D bifurcated braided structures for system-adaptable and integrated triboelectric sensing

Textiles are a flexible framework for devising soft triboelectric nanogenerators (TENGs) that can monitor or harvest mechanical energy generated from body motion. Despite various structures and impressive performance, integrated textile TENGs that can regulate the contact-separation between triboelectric materials are rarely explored. Herein, we report a programmable three-dimensional (3D) braiding strategy to construct Y-profile bifurcated textile TENGs (3D Y-TENG) by the industry-compatible hexagonal braider. Through the regulation of interlaced and bifurcated regions along 3D Y-TENGs, different contact-separations can be obtained. 3D Y-TENGs were constructed by braiding two sets of core-sheath yarns with nylon and polytetrafluoroethylene (PTFE) as the triboelectric materials, with both yarns exhibiting exceptional abrasion resistance (i.e., 3000 cycles of abrasion without structural disintegration). Five 3D Y-TENG with different bifurcation patterns were designed and fabricated to tailor the contact-separation, all presenting triboelectric response towards mechanical compressing, stretching, and bending. 3D Y-TENGs are featured with remarkable stretchability, softness, flexibility, foldability, and mechanical endurance, enabling their comfortable contact with the human body. This work presents programmable braided structures that can be tailored, adapted, and integrated with different systems for seamless electronic garments.