Cultivating Fully Biomass Pressure Sensors for Gait Analysis

Incorporating biomass (e.g., bacterial cellulose, BC) pressure-sensing structures into plantar monitoring technologies could effectively defend users against insecure wear and inaccurate detection, while their capability in sensing pressure continuously when subjected to large pressure is hindered by their natural two-dimensional structure. Here, we present a microbial engineering strategy for fabricating hierarchical fully biomass pressure sensors (HFBPSs) with sufficient sensing capabilities and good structural stability for plantar pressure detection. Particularly, the incorporation of the biobased material loofah enables HFBPS to adopt a hierarchical structure from micro- and nanostructured sensing networks, allowing for dynamic changes in the series-parallel configuration of the circuit under large pressure. This innovative structure design breaks the bottleneck of low operating range encountered by traditional rigid two-dimensional BC pressure sensors, ensuring the HFBPS with ultrahigh sensitivity (2.82 kPa-1) and wide detection range (0-600 kPa). In addition to stably monitoring gait motions, the HFBPS integrated into smart insoles can recognize nonstandard Tai Chi movements. Our HFBPS with exceptional pressure-sensing performance provides significant impact on the future development of smart insoles for plantar monitoring.