Highly stable and sensitive cellulose hydrogel piezoresistive sensors prepared from sorghum stalk/PVA composite materials

This study utilized natural sorghum straw as raw material, leveraging its material advantages of high cellulose content, low lignin and hemicellulose content, and long-fiber structure. By forming a hydrogen-bonded cross-linked network with polyvinyl alcohol (PVA), a high-performance piezoresistive sensor was developed to enhance its sensitivity and stability. Experimental results demonstrate that the sensor exhibits a sensitivity of 0.9 kPa − 1 under low-pressure conditions, 0.45 kPa − 1 under medium-pressure conditions, and further increases to 0.85 kPa − 1 under high-pressure conditions. Experimental data confirm the sensor’s long-term stability and sensitivity across the 10–120 kPa pressure range, with a minimum detection limit of 4.9 Pa. After 10,000 cyclic tests, it maintains excellent repeatability under repeated loading conditions, with a response recovery time of 25–50 ms. Furthermore, manufacturing costs were significantly reduced, achieving total cost savings of 96 %. The sensor has been successfully applied in detecting signals such as human motion, electrocardiograms, and sound, as well as in monitoring signals from pressure sensor arrays, demonstrating reliable practical performance. In summary, the piezoresistive sensor utilizing natural sorghum straw cellulose as its core conductive structure provides an efficient, reliable, and low-cost solution for pressure signal detection, promising to advance technological progress in related fields.