posted: 09/10/2021
Se-Um Kim, a postdoctoral researcher in Shu Yang’s lab, together with fellow postdocs, Young-Joo Lee and Dae Seok Kim, and graduate students Jiaqi Liu and Haihuan Wang, have developed a new photonic display platform via pneumatic inflation of thin membranes made from the main-chain chiral nematic liquid crystalline elastomers (MCLCEs), where the liquid crystal mesogens are arranged in a helix. By taking advantage of the large elasticity anisotropy and large Poisson’s ratio (> 0.5), the researchers geometrically program the size and the layout of the encapsulated air channels to achieve broadband color shift from near-infrared to ultraviolet wavelengths with less than 20 % strain perpendicular to the helical axis of MCLCEs. Each channel could be individually addressed as a color “pixel” to match with surroundings or to display 7-segment digits. It overcomes physical constraints in traditional photonic crystals made from isotropic materials. The large degree-of-freedom in the layout of the pixels and the air channels, together with unique mechanochromic performance of MCLCEs offers new insights to create new biomimetic, highly responsive and complex photonic devices with relatively simple operations.
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