Self folding weft-knit architectures as capacitive sensors

Textile manufacturing, particularly weft-knitting, allows for an almost infinite range of surface and mechanical properties. Researchers have studied self-folding knits at a range of scales from the fiber to the sheet level, where the 3D curvature leads to complex mechanical and kinematic responses that are functionalized with the incorporation of conductive yarns. The weft-knitting process allows us to route arbitrary conductive pathways and create capacitive strain sensors. We present a simple physics-based origami model of self folding weft-knit textiles that captures both the kinematics and electric response of the system. By controlling the folding pattern of the textiles, we tune the strain-capacitance relationship of these textiles to create optimized sensors for applications including wearables and soft robotic skins.