Biomimetic Multiscale-Structured Biomass Graphene/Polyurethane Sponge Composite for Flexible Pressure Sensors and...

The development of furniture cushioning materials that combine excellent mechanical properties with sensing capabilities is essential for non-intrusive, long-term health monitoring. This study presents a multifunctional conductive sponge (MAPU) that synergistically integrates the macroscale mechanical support of a polyurethane (PU) sponge with the microscale sensing characteristics of aerogels through bionic multiscale structural design. Biomass-derived graphite nanoflakes serve as the conductive units to in situ construct a 3D interpenetrating aerogel network on the PU sponge skeleton. This unique heterogeneous structure retains the flexibility and elasticity of PU sponge while providing exceptional piezoresistive sensing performance, including high sensitivity (0.821 kPa^-1 in the 0-53 kPa range), a wide response range (up to 242 kPa), fast response time (≤ 50 ms), and outstanding cycling stability (> 30 000 cycles). Equally important, MAPU also demonstrates washability, flame retardancy, breathability, and sound absorption, making it practical for household applications. An intelligent mattress composed of a MAPU sensor array enables real-time monitoring and precise recognition of sleep postures, along with bedsore risk alerts. This work offers a high-performance, multifunctional, and high-safety core material solution for advanced smart home technologies and continuous health monitoring systems.