Development of All-Polymer Two-Way Shape Memory Micronano Fiber Fabric with Dual Stimuli-Responsive Capabilities

Shape memory polymers (SMPs), as a class of smart materials capable of altering their configurations in response to external stimuli, have garnered significant research attention. However, current studies on SMPs are limited by restricted response conditions, one-way responsive mode, and restricted adaptability. In this work, a core–shell micronano fiber membrane (T-P) with polyurethane elastomer (TPU) as the core layer and poly(vinylidene fluoride) (PVDF) as the shell layer was fabricated via coaxial electrospinning. The T-P was further integrated with a micronano fiber membrane (P–P) composed of a blend of poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVA) to construct a bilayer-structured all-polymer P–P/T-P. Owing to the significant contrast in hydrophilicity, thermal properties, and mechanical properties between the two layers, the developed P–P/T-P exhibited excellent dual stimuli-responsive capabilities and two-way shape memory functionality. Under temperature-responsive process, the P–P/T-P achieved a recoverable bending angle of 75° with a shape recovery ratio of 98.67%. Under humidity-responsive process, the P–P/T-P achieved a recoverable bending angle of 32 ° with a shape recovery ratio of nearly 100%. The developed P–P/T-P was further applied to the responsive unit structure of smart windows, providing a strategy for the development of SMP-based intelligent devices adapted to diverse environments.