Triple Stimuli‐Responsive Flexible Shape Memory Foams with Super‐Amphiphilicity

Abstract Highly porous multi‐responsive shape memory foams have unique advantages in designing 3D materials with lightweight for varied applications. Herein, a facile and efficient approach to fabricating a thermo‐, electro‐, and photo‐responsive shape memory composite foam is demonstrated. A specific multi‐step carbonization protocol is adopted for transforming commercial melamine sponge (MS) to highly porous carbon foam (CF) with robust elastic resilience, efficient electrothermal/photothermal conversions, and super‐amphiphilicity. It is a novel proposal for CF to take the dual role of the elastic supporting framework and 3D energy conversion/transmission network without any functional fillers. The composite foam cPCL@CF incorporates the CF skeleton with in situ crosslinked polycaprolactone (PCL) layers, which exhibits high conductivity (≈140 S m⁻¹) and excellent light absorption (≈97.7%) in the range of 250–2500 nm. By triggering the crystalline transition of PCL, the composite foam displays sensitive electro‐ and photo‐induced shape memory effect (SME) with outstanding shape fixation ratio (R_f) and recovery ratio (R_r). Thanks to the super‐amphiphilicity and high electrical conductivity, the cPCL@CF composite foam can give rapid and distinguishable electric signals upon tiny drips of salt solutions or lithium‐ion battery (LIB) electrolytes, making it a new type of sensor for detecting electrolyte leakage.