Mechanochromic Response of Spiropyran‐Incorporated Liquid Crystalline Elastomer Network and the Mechanochromic Enhancement by Nano Zinc Oxide

Abstract Spiropyran (SP) based mechanochromic systems are intensively interesting in the research area of mechanochromic materials. Herein, an SP mechanophore is chemically incorporated into a liquid crystalline elastomer (LCE) network through Michael addition. The rigidity of mesogens and the orientation of polymer main chains, in which the aligned mesogens and SP moieties are covalently attached, facilitate the transduction of applied force to SP mechanophore to trigger mechanochromic reaction. The LCE network provides enough elasticity for mechanochromic activation. The obtained SP‐LCEs demonstrate strong and reversible mechanochromic response upon mechanical compression. The mechanochromic efficiency and sensitivity are substantially enhanced by doping the SP‐LCE matrix with nano zinc oxide such that it is easy to write on the material surface by using a thin iron wire. The authors hope such SP‐LCE materials will be further developed for real‐time stress detection applications.