A Study on Elastic Behavior of Liquid Crystal Phase of DNA Polymers Evaporating on Geometric Template

Evaporation process is a complex dynamical system in which fluid flow, known as ‘Coffee ring effect’, continues to occur and influenced by many factors such as the types of solute, wettability with the substrate, and the evaporation rate. Understanding the phenomenon is positively necessary for providing insights associated with fundamental science and engineering application.<br/>For the improvement, we delved into evaporation process, deposition mechanism and liquid crystal (LC) phase expression of DNA solution on flat substrate and micro-post template and controlled the orientation and morphology of DNA molecules using solution coating method. One of the biopolymers, DNA has recently emerged as a building block because it is abundant in nature, can be functionalized by electrostatic interaction and shows liquid crystal phase depending on the concentration. Their bulk elastic properties are quite different from other materials due to concentration-dependent LC phase. Additionally, predesigned substrates can be applied for confinement and deformation of triple-phase contact line. Then, unique and complex structure can be formed spontaneously due to the interaction between the elastic properties of DNA and confinement effect of the substrate.<br/>Here, we conducted the evaporation-induced experiments on geometrical template and controlled novel and sophisticated DNA microstructures. The pattern of the DNA can be modulated by shear direction and template spacing. This will help to understand the self-assembly of DNA molecules in confinement effect and can provide applications to bio-template for polymers, liquid crystals or other nanoparticles.