Spontaneous formation of micrometer-scale liquid crystal droplet patterns on solid surfaces and their sensing applications

Abstract

In this study, we report spontaneous formation of two characteristic micrometer-scale liquid crystal (LC) droplet patterns on solid surfaces and also demonstrate the application of the designed LC platform to construct new types of LC-based sensors. By simply spreading LCs dissolved in organic solvents on glass microscope slides, we observed one- and two-dimensional LC droplet patterns with distinctive optical textures that represent different orientations of LCs under a polarized microscope. LC droplets supported on surfaces exhibited high stability during temperature-induced phase transitions of LCs. In addition, based on the distinguishable optical appearance of the LC droplet patterns, their applications in monitoring the presence of water vapors, amphiphiles, and vapors of volatile organic compounds (VOCs) were demonstrated. These results indicate that the surface-anchored LC droplets show high promise for the development of simple, robust, and versatile LC pattern-based sensing devices for real-time and label-free detection of chemical and biological events.