Preparation of a Mechanochromic Elastomer using Liquid Crystal Dispersed in Polymer

We have designed an inexpensive and sensitive mechanochromic system. Our system is prepared by a simple emulsion procedure of nematic liquid crystal in polydimethylsiloxane (PDMS). The resulting polymer dispersed liquid crystal (PDLC) exhibits a transmission change of 50% as a response to strain. Here we characterize the morphological, optical, and mechanical factors behind this transmission change. Understanding this mechanochromic behavior is essential for developing precise and reliable methods to tune a material’s optical properties. We propose a new model that illustrates how mechanical strain modifies the polymer-liquid crystal interface and the nematic director fluctuation within the liquid crystal droplets. We propose that both of these factors play critical roles for the transmission change in PDLC samples. This work lays a new foundation for developing innovative mechanochromic devices, including smart windows and biomedical pressure sensors.