(728a) Tunable Macroporous Photonic Crystals Enabled By Shape Memory Polymers
Shape memory polymers (SMPs) have been extensively studied for applications ranging from biomedical devices (e.g., stents) to smart surfaces. However, most of the currently available SMPs are heat or light sensitive. Here we demonstrate a new pressure-sensitive SMP that enables the rapid recovery of the memorized shapes by applying a very small pressure. By combining this new type of SMP with self-assembled colloidal crystals created by a scalable doctor blade coating technology, we have developed tunable macroporous photonic crystals showing large optical stop band shifts triggered by a small pressure change. The optical responses of the pressure-sensitive photonic crystals are simulated by using a scalar-wave approximation (SWA) model and the theoretical results match well with the experimental data. We have also demonstrated that nanoporous smart coatings can be templated by using self-assembled colloidal nanoparticles as sacrificial scaffolds. The resulting SMP coatings exhibit tunable anti-glare properties and the experimental reflection measurements agree with the numerical simulations using a finite-difference time-domain (FDTD) model.