Broadband and Pixelated Camouflage by Exploiting Large Poisson Effect in Main-Chain Chiral Nematic Liquid Crystalline Elastomers

Inspired by cephalopod’s skin, the Yang lab creates an artificial chromatophore that can change colors instantly—from near-infrared to visible to ultraviolet—on demand, by inflating thin, flexible membranes made from cholesteric liquid crystal elastomers, where the mesogens are arranged in helical shapes. As the membrane is placed on top of a cavity and inflated, the pitch of the liquid crystal helix is reduced, changing the wavelength of light that is reflected at the viewer. The large and elastic anisotropy in the helical structure together with the large biaxial Poisson’s ratios allows for broadband display from red to blue with a small strain.