KumihImO: Braids with Configuration-Tunable Sensing and Output

Abstract

Braided cords (kumihimo) are a traditional Japanese textile craft combining flexibility, strength, and aesthetic beauty. While e-textile research has explored weaving, knitting, and embroidery as fabrication structures, braiding remains largely unexplored as a substrate for interactive textiles. We present KumihImO, a design and fabrication approach that integrates conductive and thermochromic threads into braided cords with both sensing and visual-output capabilities. We characterize how braiding configuration (strand count, placement pattern, and layer structure) affects electrical resistance under tension, at knot positions, and across knot counts. Our results show that pattern choice can tune a cord's role as a high-sensitivity tension sensor, a stable conductive trace, or a knot-count detector using the same yarn. We further integrate thermochromic dyeing to enable reversible, heat-driven color change as a visual output channel, unobtrusive enough to blend naturally with traditional craft objects. We demonstrate the approach through three application prototypes rooted in Japanese traditional craft.