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 SiO₂ 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.