Bio-inspired design of Mechanochromisms via surface engineering

A bilayer structure composed of polyvinyl alcohol composite thin film atop thick polydimethylsiloxane substrate was prepared. The bilayer structure shows dynamic strain-responsive optical properties. The transition between a transparent state to an opaque state can be easily achieved by uniaxially stretching and releasing the device. Also, a series of derivative mechanochromisms with capabilities of switch “on/off” fluorescence, change fluorescent color, reveal/hide information upon mechanical stimuli are prepared. These devices feature virtually no changes in optical/mechanical properties after being repeatedly stretched and released thousands of times, promising for widespread applications.