Octopus-inspired graphene nanoplatelets@microfibrillated cellulose/natural rubber sponges with high sensitivity and broad response range for all-scale physiological mechanical signals monitoring

Amid surging demand for intelligent health monitoring, developing flexible pressure sensors with high sensitivity, broad range pressure sensing, and mechanical robustness for all-scale physiological monitoring remains challenging. In this study, microfibrillated cellulose (MFC) featuring an octopus neuron-mimic structure was first obtained by dissociating CMF utilizing ultrahigh-speed vortex technology. Subsequently, graphene nanoplatelets (GNPs) were electrostatically anchored onto MFC to form octopus neuron-inspired highly sensitive GNPs@MFC conductive fibers. This distinctive bioinspired fiber was ingeniously employed to construct a GNPs@MFC/NR (natural rubber) conductive sponge with an octopus-mimic distributed neural network and pressure-dissipation modes through the combined technology of ice templating and hydrothermal vulcanization. Leveraging the fibrillated structure of MFC, polygonal pore structure, and Y-shaped nodes, this sponge achieved ultra-fast responsive speed (35/70 ms), high sensitivity (21.94 kPa − 1 , < 0.7 kPa), broad range sensing (0.001% micro-strain, 1015 kPa), and exceptional mechanical robustness (> 96% water recovery after 90% strain compression). GNPs@MFC/NR sponge-based flexible pressure sensor successfully identified subtle pressure signals (e.g., pulse, airflow), medium pressure signals (e.g., joint movement), and high-pressure signals (e.g., plantar pressure). This bioinspired strategy, inspired by octopus neurons, distributed neural networks, and high-pressure dissipation modes in NR sponges, provides rich possibilities for developing multifunctional pressure-sensing materials.