Preparation and performance of balsa wood-based carbon sponge /TPU composite pressure sensor

In recent years, flexible pressure sensors with three-dimensional mesh structure show high reversible compressibility and good sensitivity, and their complex network shape is also conducive to the construction of stable conductive network, which is widely used in human health monitoring, wearable devices, medical diagnosis and other fields. In this study, a carbonized wood sponge(CWS)/TPU composite pressure sensor with three-dimensional layered structure based on natural balsa wood was designed to construct a stable three-dimensional conductive network and optimize the sensing performance. The catalytic treatment, carbonization process, sensing performance and human applicability of the sensor were characterized. The results show that the carbon yield of the light wood-based CWS/TPU sensor by catalytic treatment and high temperature carbonization can reach 20.15%, the compressive strain can reach at 60%, and the maximum pressure sensing sensitivity (S) can reach 12.87 kPa⁻¹ in the pressure range of 0-4 kPa. Moreover, the sensor still has good sensing stability and environmental stability even after 5000 compression/release cycles, showing good sensing performance. The sensor was successfully used to monitor hand movement, walking and pulse in real time, which shows the potential application value of the sensor in motion and health monitoring.