Stretchable, Breathable and Washable Textile Sensor for Human Motion Monitoring

Advancing the accuracy and ubiquity of in-situ human motion monitoring requires the development of soft wearable sensors that maximize wearer’s comfort. To translate wearable sensing technologies beyond laboratory settings and into<br/>real-world applications, it is important to develop light-weight, breathable sensors that can be seamlessly integrated into commercial clothing and interface directly with human skin without losing signal fidelity. Here, we report the fabrication of<br/>a soft textile capacitive sensor capable of describing everyday human motions due to its high conformability and mechanical flexibility. Unlike established capacitive strain sensors, which usually rely on stretchable elastomers, our sensor is constructed out of thin films of breathable adhesive and fabrics. Our soft sensor exhibits good stretchability (&gt;90%), excellent durability (repeating cyclic deformation &gt; 5000 cycles), and high water-vapor transmission rate (∼ 50g/h.m2) which allows sweat evaporation, an important parameter of comfort. Additionally, we verified that our sensor can function under analogous conditions to human body temperature and sweat (89% relative humidity and 35 °C) and function after washing. The sensor also shows highly stable capacitance over a high range of excitation frequencies (up to 1 MHz), facilitating its implementation with commercial circuitry. Furthermore, the manufacturing process of these sensors can be scalable and customizable at low cost, paving the way for the next generation of flexible and comfortable wearable sensors.