Flexible and Pressure-Responsive Sensors from Cellulose Fibers Coated with Multiwalled Carbon Nanotubes

Composite cellulose-based materials have shown increasing potential in wearable and flexible hybrid electronics for large-scale deployment because of their flexible, cost-effective, abundant, and biodegradable features. A flexible cotton cellulose-incorporated multiwalled carbon nanotube (MWCNT) based pressure sensor was fabricated. First, the cotton cellulose fibers were swelled in water solution containing sodium hydroxide and urea. Second, the MWCNTs were dispersed uniformly in the cellulosic matrix. Then, cellulosic pressure sensors were formed with a water bath process. The porous and interlaced conductive networks in the pressure sensors containing 10 wt % of MWCNTs exhibited a sensitivity about of −0.0197 kPa –1, a response time of about 20 ms, a recovery time of about 20 ms, and a wide workable pressure range from 0 to 20 kPa. Further, the practical piezoresistivity of sensor specimens was investigated. The proposed pressure sensors are prospective for various applications including smart clothing, electronic skins, medical diagnosis, and treatment.