(54b) Modularizable Liquid Crystal-Based Open Surfaces Enable Programmable Chemical Transport and Feeding Using Liquid Droplets
AIChE Annual Meeting
2022
2022 Annual Meeting
Engineering Sciences and Fundamentals
Fundamentals of Interfacial Phenomena II
Monday, November 14, 2022 - 8:15am to 8:30am
Thermotropic liquid crystals (LCs), a particularly promising class of anisotropic liquids, exhibit a remarkably diverse group of colloidal and interfacial phenomena with unprecedented complexities and functionalities. For instance, LC films immersed in water have shown the ability to optically respond to chemicals or external fields and release cargo following an LC phase transition. These previous findings lead us to hypothesize that the intrinsic stimuli-responsiveness of LCs enables the design of a novel class of functional surfaces, which combine the programmable chemical feeding of microfluidics systems and the easy fabrication of open surface platforms that allow for the programmable feeding of chemical reagents to droplets. Very recently, we reported the design of a porous LC polymeric network to stabilize LC films against water droplet-induced dewetting, enabling chemical feeding to droplets on an LC surface platform. However, the integration of these LC surfaces to achieve the programmable and automatic release of multiple chemicals to manipulate (bio)chemical reactions in droplets without droplet pinning, a prerequisite for the design of advanced open surface droplet reactors, has not yet been achieved.
In this work, we designed and implemented an LC-based open surface platform that can encapsulate chemical reagents for future release into a liquid droplet on the surface via an LC phase transition. When combined with their natural water repellency and self-healing properties, our LC-based open surface platforms proved to be modularizable â where LC surfaces loaded with different chemical reagents can be freely assembled to program the order and quantity of chemical reagents released into the droplet on the surface â which enables a variety of sequential and parallel reactions and material synthesis including crystallization and (co)polymerization within water droplets. Additionally, we developed an LC surface-based device that is simple to operate and uses droplets as carriers to automatically control the feeding of cell signaling modulators for the simultaneous differentiation of human induced pluripotent stem cells (hiPSCs) into different cell types, e.g., endothelial progenitor cells and cardiomyocytes. Overall, the advances reported in this work provide design principles for novel, LC-based open surfaces for droplet carriers and reactors, offering an opportunity to achieve unprecedented levels of controllability, responsiveness, and automation for use in materials synthesis and regenerative cell therapy.