PEDOT:PSS/PDMS-Coated Cotton Fabric for Strain and Moisture Sensors

In this work, we have successfully developed a flexible, lightweight, and washable strain and moisture sensor textile fabric by printing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/polydimethylsiloxane-b-polyethylene oxide (PEDOT:PSS/PDMS) conductive polymer composite on knitted cotton fabric. A 60.2 kΩ/sq surface resistance has been obtained at a 30% ratio of PDMS to PEDOT:PSS at 0.012 g/cm2 solid add-on. The coated fabric was washed at 30 °C for 30 min in the presence of a standard detergent. It was observed that there was a 5.3% increase in surface resistance, i.e., 63.4 kΩ/sq. After coating, the fabric could still be stretched up to the infliction elongation of the fabric, i.e., 40%, with a significant change in surface resistance that makes it usable as a strain sensor. In addition, the conductive fabric showed a drop in surface resistance with an increase of the moisture regain up to 150%.