Cellulose hydrogels with high response sensitivity and mechanical adaptability for flexible strain sensor and triboelectric nanogenerator

A novel cellulose hydrogel (MCC/SA20/MCC-g-P(AA-co-AM-AMPS)) was prepared using a simple hybridized multiple cross-linked network synthesis method. It have excellent moisture absorption and retention, good mechanical properties, and high strain sensitivity. Therefore, the flexible wearable strain sensors were prepared to enable the detection and monitoring of human body movement in an effective and timely manner and to capture different sensing signals. In addition, it can also be assembled as friction nanogenerators (TENG), which produces a stable alternating voltage and is self-powered for small electronic devices. This study provides an effective strategy to overcome the problems of water loss, poor mechanical properties, and low conductivity sensitivity of hydrogels, and offers opportunities for accurate identification and monitoring of flexible strain sensors, green energy harvesting, and power supply applications for small self-powered sensors, which is expected to broaden the application of cellulose hydrogels in the field of flexible smart sensing devices. [Display omitted] •A novel multiple cross-linked cellulose hydrogel (MCC/SA20/MCC-g-P(AA-co-AM-AMPS)) with high sensitivity and good mechanical adaptability was designed and prepared.•This study provides an effective strategy to overcome the problems of water loss, poor mechanical properties, and low conductivity sensitivity of hydrogels.•It can be assembled as a strain sensor, which can accurately identify and monitor various motion states of the human body. Meanwhile, it was also assembled as a single-electrode friction nanogenerator (TENG) for self-powered supply applications for small devices, which effectively broadens the applicability of cellulose hydrogels. Cellulose hydrogels are widely regarded as green and environmentally friendly flexible electronic materials. Herein, a novel multiple cross-linked cellulose hydrogel (MCC/SA20/MCC-g-P(AA-co-AM-AMPS)) with high sensitivity (gauge factor = 440, 670 %, 60 ms) and good mechanical adaptability was designed and prepared. The prepolymer (MCC-g-P(AA-co-AM-AMPS)) was introduced into the microcrystalline cellulose/sodium alginate (MCC/SA) hydrogel network to form a multiple cross-linked network structure, which effectively enhanced the tension and elasticity of the cross-linked network, and improved the mechanical adaptability and sensitivity of the hydrogel. Additionally, it was assembled as a strain sensor that can accurately identify and moni