Multifunctional Directional Water Transport Fabrics with Moisture Sensing Capability

Previous fabrics with directional fluid transport capability typically have a single function to transport liquid. Multifunctional directional fluid fabrics are highly desirable for making "smart" textiles but remain a challenge to develop. In this study, we have for the first time prepared a multifunctional, directional water transport fabric. By using a two-step coating process, we applied polypyrrole (PPy), a conducting polymer, on one side of a hydrophilic fabric (cotton). We showed that the single-side PPy-coated fabrics had reasonable conductivity (surface resistance in the range of 43-54 kΩ/□) and a one-way water transport function. We further showed that by integrating metal-plated nylon wires on the two sides, the fabric can be used as a capacitive sensor to sense water content in the fabric. The conducting layer enables the sensor device to have a sufficient capacitance response. Reasonable integration of the metal electrodes allows the device to have a minimal effect on the directional water transport and breathability of the fabric. Such a novel multifunctional fabric may find applications in making "smart" clothing.