(441c) Unconventional Nanoscopic Shape Memory Effects Exhibited By Novel Multi-Stimuli-Responsive Shape Memory Polymers
Shape memory polymers (SMPs) are stimuli-responsive materials that can change their shapes upon application of an external stimulus (e.g., heat and light). They have been extensively exploited for a wide spectrum of technological applications ranging from smart biomedical devices to aerospace morphing structures. Unfortunately, most of the currently available SMPs are thermoresponsive and they suffer from heat-demanding programming and recovery processes. Additionally, the intriguing nanoscopic shape memory effects, which could significantly enhance the response speed and greatly expand the application aspects of SMPs, are largely unexplored. Here we report unconventional nanoscopic shape memory effects exhibited by a new series of multi-stimuli-responsive SMPs. When combined with a unique macroporous photonic crystal structure templated from self-assembled colloidal crystals, these smart SMPs enable unusual âcoldâ programming and instantaneous shape recovery at ambient conditions triggered by multiple untraditional stimuli, such as static pressure, lateral shear stress, a large variety of liquids and vapors, and ultrasonic waves. Importantly, striking chromogenic responses associated with a full all-room-temperature shape memory cycle could render a new and sensitive optical technology for investigating the intriguing nanoscopic deformation and recovery of SMPs.