A low-cost fabrication technique for direct sewing stretchable interconnetions for wearable electronics

Here, we present a facile method for rapid fabrication of low-cost, stretchable electrical interconnections for wearable electronics. Using a commercial sewing machine, thin metallic wires are sewn onto the wearable materials in a double-stitch zigzag pattern, with the second stitch being a water-soluble polyvinyl alcohol (PVA) thread. The stretchable pattern is secured onto a clothing (e.g., a glove) with a stretchable elastomer coating followed by dissolution of the PVA thread in water. The interconnections maintain a constant electrical conductivity for strains up to 50 % and bending cycles over 15000. As a proof of concept implementation, we sewed interconnects and a soft capacitive force sensor onto a latex glove to create a wearable tactile sensor with a linear sensitivity of 96 fF/N.