Optical Characteristics of Stretchable Chiral Liquid Crystal Elastomer under Multiaxial Stretching

Chiral liquid crystal elastomers (CLCEs) are soft photonic materials that exhibit both the photonic characteristics of nanoscale periodic helical structures and mechanical properties of rubber. Owing to its elasticity, the structural color of CLCEs can be tuned through mechanical deformations known as mechanochromism. Thus far, there is significant research attention to exploring the mechanochromism of CLCEs. However, most studies have only discussed the color shifting of CLCEs under uniaxial deformation. Therefore, the optical and chiral structural deformation behaviors of CLCEs under multiaxial stress are not well understood. This study investigates multiaxial (uniaxial, biaxial, and out-of-plane) stretching-induced helical structure change and the resulting optical properties of CLCEs. The results confirm that uniaxial stretching leads to a loss of intrinsic circular polarization selectivity in CLCEs due to helix unwinding deformations, while biaxial and out-of-plane stretching maintain circular polarization.