Bending-induced wideband reflection wavelength tuning of cholesteric liquid crystal elastomer

Abstract

Cholesteric liquid crystal elastomers (CLCEs), which exhibit selective reflection arising from their helical molecular structure, are receiving considerable attention because they can deform largely due to the crosslinked polymer chains. Reflection wavelength of a CLCE film can be tuned by mechanical stretching, which induces the helical pitch change. However, the stretch-induced tuning of reflection wavelength has some issues such as a large load required and a limited tuning range. In this study, reflection wavelength of a CLCE film is tuned facilely and widely by bending. Bending load required for the reflection tuning is much lower than stretching load. Furthermore, we can tune reflection wavelength of the CLCE film over 300 nm.