456135 Bio-Inspired Sensitive and Reversible Mechanochromisms Via Surface Engineering

Tuesday, November 15, 2016: 8:48 AM
Golden Gate 5 (Hilton San Francisco Union Square)
Songshan Zeng1, Dianyun Zhang2, Wenhan Huang3, Zhaofeng Wang1, Stephan Freire1, Xiaoyuan Yu4, Andrew Smith1, Emily Huang1, Helen Nguon1 and Luyi Sun1, (1)Department of Chemical and Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT, (2)Department of Mechanical Engineering, University of Connecticut, Storrs, CT, (3)Heyuan Polytechnic, Heyuan, China, (4)South China Agricultural University, Guangzhou, China

In nature, some marine organisms, such as Vogtia and Cephalopods, have evolved to possess camouflage traits by dynamically and reversibly altering their transparency, fluorescence, and coloration via muscle controlled surface structures and morphologies. To mimic this display tactics, we designed similar deformation controlled surface engineering via strain-dependent cracks and folds to realize four types of novel mechanochromic devices: (1) transparency change mechanochromism (TCM), (2) luminescent mechanochromism (LM), (3) color alteration mechanochromism (CAM), and (4) encryption mechanochromism (EM), based on a simple bilayer system containing a rigid thin film and a soft substrate. These devices exhibit a wide scope of mechanochromic response with excellent sensitivity and reversibility. The TCM device can reversibly and instantly switch between transparent and opaque state upon stretching and releasing. The LM can emit intensive fluorescence as stretched with an ultrahigh strain sensitivity in comparison to strain sensors based on electrical resistance change. The CAM can turn fluorescent color from green to yellow to orange as stretched within 20% strain. The EM device can reversibly reveal and conceal any desirable patterns. These novel devices are promising for applications in smart windows, dynamic optical switches, strain sensors, encryption, etc.

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See more of this Session: Multifunctional Composites
See more of this Group/Topical: Materials Engineering and Sciences Division