Control of the Properties of Micrometer-Sized Actuators from Liquid Crystalline Elastomers Prepared in a Microfiuidic Setup

摘要

In this article new results on the preparation of monodisperse particles from a liquid crystalline elastomer in a microfluidic setup are presnted. For this, droplets from a liquid crystalline monomer are prepared in a microfluidic device and polymerized while they are flowing inside a microtube. The particles obtained by this method possess an internal orientation, which gives them actuating properties. When they are heated into the isotropic phase of the liquid crystalline material they show a reversible change in shape whereby they change their length in one direction by almost 100%. It is shown how the variation of experimental parameters during their synthesis impacts the properties of these micro-actuators. Influence over their primal shape, the strength of their shape changing properties, their size, and their mechanical properties is demontrated. From the systematic variation of experimental parameters a deep understanding of the complex processes taking place in a flowing droplet of a liquid crystalline material is obtainted. Additionally NMR analysis and swelling experiments on these actuating materials are provided.