(262h) Reusable Chromogenic Sensors Enabled By Novel Multi-Stimuli-Responsive Shape Memory Polymers

Authors: 
Leo, S. Y., University of Florida
Jiang, P., University of Florida
Here we report novel chromogenic sensors that exhibit easily perceived color changes when exposed to different external stimuli, such as pressure, shear stress, ballistic impact, a large variety of vapors and liquids, heat, and acoustic wave. These multifunctional sensors are reusable, inexpensive, light weight, consuming no electrical power, and very small footprint, promising for a spectrum of applications ranging from user-friendly environmental monitoring to specifically sensing chemicals. This new technology is enabled by integrating scientific principles drawn from two disparate fields that do not typically intersect - the fast-growing photonic crystal and shape memory polymer (SMP) technologies. The active components of the SMPs are thin macroporous photonic crystal layers (only a few mm thick) which are fabricated by using self-assembled, 3-D highly ordered colloidal crystals as structural templates. This microscopic thin-film configuration renders orders of magnitude faster response speed than bulky SMP samples in traditional applications. In addition, by leveraging easily perceived color changes associated with the unconventional all-room-temperature shape memory cycles enabled by the recent discovery of a new series of multi-stimuli-responsive SMPs, sensitive and specific detection of an analyte in a multicomponent solution, such as ethanol in gasoline with a detection limit of 10 ppm, has been demonstrated.