PileUp: A Tufting Approach to Soft, Tactile, and Volumetric E-Textile Interfaces

We present PileUp, a tufted pile e-textile sensing approach that offers unique affordances through the tactile expressiveness and richness of its continuous, threaded-volume construction. By integrating conductive yarns in looped or cut pile forms, PileUp transforms soft 3-dimensional textiles into multimodal sensors capable of detecting mechanical deformations such as pressure, bending, and strain, as well as environmental conditions like moisture. We propose a design space that outlines the relationships between texture, form factor, and sensing affordances of tufted textiles. We characterize electrical responses under compression, bending, and strain, reporting sensor behaviors. To demonstrate versatility, we present three application scenarios in which PileUp sensors are seamlessly integrated into soft fabrics: a meditation rug with multi-zone sensing, a fleece sleeve that detects arm motion, and a moisture-sensing wall art. Our results establish tufting as an accessible yet expressive fabrication method for creating integrated sensing textiles, distinguishing our work from traditional flat textile sensors.