Preparation of a Highly Sensitive and Stretchable Strain Sensor of MXene/Silver Nanocomposite-Based Yarn and Wearable Applications.

As a wearable device, highly sensitive and stretchable strain sensors should be integrated to monitor various daily actions, which include large- and small-scale strains, such as jumping, running, heartbeat, and pulse. At present, the method of preparing strain sensors is mainly to impregnate or load materials like graphene, carbon nanotube, and their union products on elastic substrates to obtain highly sensitive characteristics. Both well-known carbon-based and other single-dimensional nanomaterials do not have high flexibility and conductivity, which limits the improvement of sensitivity. However, a novel material MXene Ti3C2Tx has a two-dimensional (2D) sheet structure, which allows for higher electron and ion transmission rates. In addition, it is easier to be combined with other nanomaterials as a nanosubstrate, greatly improving malleability. Hence, we creatively prepared zero-dimensional (0D)-one-dimensional (1D)-2D multi-dimensional nanomaterials, which designed 0D silver nanoparticles (AgNPs) loaded on 2D MXene nanosheets and compounded with 1D silver nanowires (AgNWs). The method improves the elasticity and conductivity of traditional single-dimensional materials, wherein AgNPs built a bridge between AgNWs and MXene, which ensures continuity and a high gauge factor even at a large strain (200%) of yarn. The composite yarn strain sensor has a remarkably high strain and sensitivity, effectively monitoring the large and small deformations of various parts of the human body, whose fabric can be an electrothermal device. It has vital inspiration for the development of intelligent textiles, which would be used in medical devices, artificial skin, and other wearable fields.