Universal strategy to minimize capillary effect in textiles for high-sensitivity inkjet-printed wearable gas sensor

Textile-based wearable gas sensor technologies have attracted significant attention due to their large surface area, internal gas adsorption capability, and integrability . However, the rough and porous nature of textiles often leads to non-uniform material deposition, limiting sensor performance. Here, we propose a universal modification method using hydrophobic SiO 2 nanoparticles to reduce the capillary effect in textiles, enabling precise inkjet printing of electrodes and sensing materials. By minimizing the capillary effect, a wearable CO sensor with a highly uniform CuO nanosheets sensing layer and precise Ag interdigitated electrodes is fabricated. At room temperature, the sensor exhibits a response of 76.2 % to 10 ppm CO, with a detection limit as low as 200 ppb (14.42 % response). In conditions of high humidity (98 % RH) and significant bending (120° for 5000 cycles), the sensor still exhibits high sensitivity to 10 ppm CO. This work presents a universal method for minimizing the capillary effect in textiles, offering new possibilities for developing flexible electronics and wearable gas sensors.