A wearable strain sensor based on self-healable MXene/PVA hydrogel for bodily motion detection

Developing flexible, stretchable, and self-healing wearable electronic devices with skin-like capabilities is highly desirable for healthcare and human-machine interaction. Hydrogels as a promising sensing material with crosslinked polymer networks have received widespread attention for decades. However, sensors based on hydrogels suffer from low sensitivity and stability due to their poor electrical conductivity or the movement of nanofillers in hydrogel networks. Herein, a stable, sensitive, and self-healing strain sensor is fabricated by the Ti3C2Tx MXene nanosheets/polyvinyl alcohol (PVA) hydrogel (T-hydrogel). The introduction of MXene increases the number of H-bonds in the PVA hydrogel network and enhances the conductivity, resulting in high sensitivity, stability, and self-healing character. The self-healing T-hydrogel-based strain sensor has a performance close to that of the original sensor. In addition, the device is capable of detecting bodily motions, indicating the potential application in the field of human health monitoring and human-computer interaction.