Shape memory urushiol-Fe particle/polyurethane composite material with photothermal response for remote control and sensing

Due to fast response and precise controllability, photothermal responsive shape memory materials have developed into a promising platform for intelligent sensing systems. In this paper, we have developed a multifunctional composite material by combining molecularly-engineered polyurethane matrix with biomass photothermal nanoparticles. The shape memory polyurethane was synthesized using polytetramethylene 2000 as the soft segment, hexamethylene diisocyanate as the hard segment, and 1,4-butanediol/4,4′-dithiodianiline as chain extenders, achieving an optimized structure with coordinated balance between soft and hard segments. The urushiol-iron polymer encapsulated Fe 3 O 4 composite particles (urushiol-Fe particles) prepared through a one-step chelation/oxidation of natural urushiol and green-vitriol, provided outstanding photothermal conversion while maintaining excellent interfacial compatibility. By controlling the nanoparticle content (less than 1 wt%) to optimize interfacial interactions, the composite exhibits enhanced mechanical tensile strength (17.21 MPa), excellent shape memory performance (95.56 % fixation, 97.78 % recovery), and wide-temperature-range shape memory (37–80 °C), along with multifunctionalities including on-demand sterilization (100 % inhibition), rapid photothermal ethanol-assisted self-healing (95.58 % recovery in 30 min), durable light-triggered actuation (1000+ cycles) and precise light triggered shape deformation performance. Furthermore, the designed combination logic device driven by photothermal-environment synergy significantly improved temperature detection accuracy. This study establishes an innovative system for photothermal-responsive intelligent materials while opening new pathways for advanced sensing systems with excellent functionality and reliability. Future research should focus on overcoming thermal inertia-induced response delays and optimizing manufacturing processes to enable real-world applications across diverse fields including smart remote sensing, environmental surveillance, soft robotic systems, and biomedical instrumentation.