Hierarchical Double-Network Scaffold Based on Natural Plant Skeleton with In Situ-Polymerized PAM for High-Performance Pressure Sensing

The use of natural biomass to construct sustainable, flexible sensors has gained significant attention. In this work, we report a cellulose-polyacrylamide (PAM) dual-network architecture derived from corn stalk pith (CSP). A cellulose scaffold is first obtained via in situ delignification and dissociation of cellulose microfibrils from CSP, followed by the in situ polymerization of acrylamide (AM) and MXene (MX) to form the PAM network, producing the composite (CSP-AM-MX). The resulting dual-network structure exhibits outstanding elasticity and a favorable sensing performance. It can withstand up to 80% compressive strain with extremely low hysteresis and maintains structural integrity without noticeable deformation after 1000 loading–unloading cycles. The CSP-AM-MX sensor shows excellent electrical conductivity and sensing sensitivity, enabling reliable operation over a broad pressure range of 9–705 kPa with a fast response time. Potential applications include human activity monitoring, force warning systems, and Morse-code conversion. This work not only provides a green and sustainable route for valorizing agricultural waste but also demonstrates the promising potential of biobased polymer networks in flexible electronics, human–machine interaction, and health monitoring.