Highly Durable and Stretchable Ti3C2Tx/PPy-Fabric-Based Strain Sensor for Human-Motion Detection

Flexible, stretchable, and wearable fabric strain sensors can easily detect human motions and monitor human health, but their utility is limited by poor stability and sensing performance. The stability and sensing performances of the fabric strain sensors are invariably determined by the fabric and conductive materials. Here, a Ti 3 C 2 T x /polypyrrole (PPy) nylon strain sensor is fabricated using a facile one-step polymerization of pyrrole (Py) monomers in the presence of Ti 3 C 2 T x suspension at 0 ° C. The Ti 3 C 2 T x nanosheets/PPy nanospheres heterostructure adhered to the nylon substrate inhibits mutual agglomeration and stacking, which provides more electron transfer pathways. The nylon substrate and two conductive materials endow the sensor with excellent stretchability (50%), low resistance (80 Ω cm −1 ), fast response (40 ms), and recovery (70 ms), a wide sensing range (0–50%), and long-term sensing function (2000 cycles). With these virtues, the prepared Ti 3 C 2 T x /PPy nylon sensor can monitor human activities effectively, including joint bending (finger, elbow, and knee) and subtle motions (carotid pulse, slight pressing, and speaking vibrations). The flexible and highly conductive Ti 3 C 2 T x /PPy strain sensor exhibits a promising sensing performance against the external strain, allowing it to be used in health-care monitoring.