Cellulose Fiber-Derived Carbon Fiber Networks for Durable Piezoresistive Pressure Sensing

It is still a large challenge to prepare compressible carbon aerogels for flexible pressure sensors from cellulose-based materials in a green and cost-effective way. Herein we demonstrate a facile strategy to fabricate a compressible carbonized cellulose fiber network (CCFN) strengthened with in situ-synthesized polydopamine (PDA), i.e., PDA–CCFN, for use as flexible pressure sensors. This strategy involves the introduction of aldehyde groups on cellulose fibers and the in situ loading of PDA on the CCFN, which improves the compressibility of the CCFN and endows the PDA–CCFN-based pressure sensor with excellent mechanical durability. The PDA–CCFN-based pressure sensor shows high sensitivity, a low detection limit, a quick response time for loading and unloading, and excellent reproducibility. It has potential applications in monitoring human activities and in wearable biosensing for healthcare. In addition, a 5 × 5 sensor array is prepared and applied for detecting spatially resolved pressures and mapping pressure distribution.