Controlled Real-Time Transition Between Bipolar and Radial Configuration of Liquid Crystal Droplets

Active matter is the study of driven many-body systems that span length scales from flocking birds to molecular motors. A previously described self-propelled particle system was made from liquid crystal (LC) droplets in water with high surfactant concentration to move particles via asymmetric surface instabilities. Using a similar system, we increase the concentration of SDS surfactant to undergo a transition from the so-called bipolar configuration to a radial configuration and cause the droplets to begin swimming at sufficiently high concentration. Using optical tweezers, we can hold and observe a single LC droplet as the surfactant concentration is increased, allowing us to watch the dynamics of LC phase transitions directly. Further, we can use the same system to explore the dynamics of confined LCs in the presence of novel, custom surfactancts used to trigger phase transitions.