Microstructured CNTs/Cellulose Aerogel for a Highly Sensitive Pressure Sensor

Flexible sensors have been applied in human health monitoring and biomedical research, but producing high-performance piezoresistive sensors at low cost is still challenging. To address these shortcomings, we proposed a microstructured carbon nanotube (CNT)/cellulose aerogel-based pressure sensor. The sensor consists of three parts, i.e., cellulose/poly(vinyl alcohol)/CNT aerogel-based sensing layer and top and bottom thermoplastic polyurethane elastomer (TPU)/silver nanowire (Ag NW) nanofiber electrode. The aerogel is fabricated using a simple freeze-drying method and an easy electrospinning method to obtain the nanofiber-based electrode. Two TPU/Ag NW nanofiber electrodes sandwiched the aerogel with a microstructure in the middle. Benefiting from the microcone and micropore structures on the nanofiber electrode, the assembled sensors show a high sensitivity of 66.4 kPa^-1, a significant detection boundary of 50 kPa, and an excellent response speed of 10 ms. The high sensing performance enables the sensor to monitor physiological signals, Morse code interactions, and gesture recognition. With the help of machine learning, the success rate of gesture recognition is as high as 98.8%. The preparation of this pressure sensor based on an aerogel shows excellent health and environmental monitoring potential as an artificial skin.