Liquid Crystal Producing the Beautiful Iridescent Color of Beetles

Abstract

In biological systems, there are many rod-like molecules which can form the liquid crystals. These molecules are widely distributed in the skeletal systems, including plant cells, insect cuticles, bone and cornea and are packed into the helical twisted structure as in the cholesteric liquid crystal, leading to the hypothesis that the molecules are oriented by self-assembly during a cholesteric liquid crystalline phase. The beautiful iridescent colors observed in some beetles are due to the selective reflection of visible lights by the periodical helical structure.