High-performance fibrous strain sensor with synergistic sensing layer for human motion recognition and robot control

With the development of flexible electronic devices and the Internet of Things technology, flexible strain sensors have shown enormous application potential. Working range and response sensitivity are two key parameters to evaluate the performance of flexible strain sensors, however, combining wide working range and high response sensitivity remains a prominent challenge for flexible strain sensors. In this work, a flexible CNT@TPU fibrous strain sensor (CTFSS) with synergistic sensing layer was prepared using electrospinning and spraying technique. Benefiting from the synergetic sensing layer composed of stable continuous CNT layer and crack-structured CNT layer, the prepared CTFSS exhibits high response sensitivity (maximum gauge factor, GFmax = 8.9 × 104) within a wide working range of 0–630%, fast response/recovery time of 120/150 ms, as well as good sensing stability and durability over 10,000 cycles. As a result, it can be used to monitor small strain such as pulse and vocal cord vibration, as well as detect large-scale human strain such as walking, running, finger bending, and elbow bending. In addition, a data glove was assembled based on the CTFSS and used for sign language recognition and mechanical palm control test, showing broad application prospects in intelligent sign language recognition and remote control of robots. Importantly, the resultant CNT@TPU fibrous membrane also possesses outstanding Joule heating and photoheating capabilities, making the CTFSS to be capable for high effective personal thermal management in harsh environments.