Impact of Textile Architecture on the Electromechanical Behavior of Conductive Carbon: Silicone Composite Strain Sensors

Stretchable strain sensors can be used to track motion or biophysical stimuli in a variety of applications, yet their adoption is hindered by complex fabrication processes and unpredictable electromechanical behavior. To overcome this limitation, we have integrated a stretchable carbon black composite consisting of commercially available materials directly onto a textile using stencil printing to realize a strain sensor. We find that the knit structure significantly influences sensor uniformity, dimensional stability, and stretchability, while yarn morphology dictates the hysteresis effect. This is demonstrated using a double weft (1 × 1 rib) and a double warp (tricot) knit. The stitch density of the textile is inversely proportional to the sensor's initial resistance and to the gauge factor, irrespective of the textile's mechanical or chemical properties. This study presents a novel model for estimating nominal resistance at a given strain near the percolation threshold, using solely the textile architecture, which can greatly assist in the development of wearable electronics in textiles.