spaceR: Knitting Ready-Made, Tactile, and Highly Responsive Spacer-Fabric Force Sensors for Continuous Input

With spaceR, we present both design and implementation of a resistive force-sensor based on a spacer fabric knit. Due to its softness and elasticity, our sensor provides an appealing haptic experience. It enables continuous input with high precision due to its innate haptic feedback and can be manufactured ready-made on a regular two-bed weft knitting machine, without requiring further post-processing steps. For our multi-component knit, we add resistive yarn to the filler material, in order to achieve a highly sensitive and responsive pressure sensing textile. Sensor resistance drops by ~90% when actuated with moderate finger pressure of 2 N, making the sensor accessible also for straightforward readout electronics. We discuss related manufacturing parameters and their effect on shape and electrical characteristics and explore design opportunities to harness visual and tactile affordances. Finally, we demonstrate several application scenarios by implementing diverse spaceR variations, including analog rocker- and four-way directional buttons, and show the possibility of mode-switching by tracking temporal data.