Carbon nanotube modified cellulose nonwovens: superhydrophobic, breathable, and sensitive for drowning alarm and motion monitoring

Due to its exceptional sensitivity and conductivity, flexible wearable sensors have received a lot of interest recently in the fields of human health monitoring and motion detection. In this work, a superhydrophobic and extremely permeable pressure sensor using multilayer hydroentanglement cellulose non-woven fabrics modified with carbon nanotubes was prepared by ultrasonic-assisted modification and impregnation. The sensor has high sensitivity (11.78 kPa^-1 in 0-5.20 kPa and 0.058 kPa^-1 in 5.20-210 kPa), fast response time (49 ms), ultra-wide pressure detection range (0–210 kPa), excellent air permeability (688 mm/s) and long-term reliability. With a 155° water contact angle, it also exhibits exceptional superhydrophobic characteristics, providing an outstanding self-cleaning effect. Importantly, the sensor has been successfully applied to monitor weak movements (pulse, voice recognition) and joint movements in real-time, which has paved the way for human health monitoring and disease diagnosis. In addition, using the superhydrophobicity and sensitivity of the sensor, it can be connected to a mobile phone via Bluetooth for remote real-time monitoring and applied to drowning alarm monitoring in underwater environments, showing great promise in practical applications.