Stretchable External Interconnects Based on a Hybrid Braiding Process

Smart garments integrated with flexible electronics hold great potential for human‐movement monitoring and personal health assessment. A key design challenge is establishing reliable stretchable interconnects among electronic modules distributed across various body locations. Although photolithography‐based stretchable interconnects offer excellent stretchability and conductivity, their production is costly, and their achievable lengths are limited by wafer dimensions. Here, we present a stretchable external interconnect constructed from textile fibers, copper wires, and latex filaments through a hybrid braiding process, achieving simultaneously high stretchability, high conductivity, and continuous manufacturing at arbitrary lengths. The interconnect exhibits low tensile stiffness up to 80% strain for enhanced wearing comfort, while under extreme loading, the textile fibers absorb most of the applied force, protecting the copper wires from damage. A mechanical model is developed to elucidate this deformation mechanism. Furthermore, the cross‐sectional geometry can be designed in either flat or cylindrical form, and the number of channels can be customized. Finally, we demonstrate the utility of this stretchable external interconnect in a multi‐channel ECG‐monitoring smart fitness garment. These results indicate that the developed stretchable external interconnect holds significant promise for smart‐garment applications.