Patterning of microstructures of organic molecules using electric field and its applications

Abstract

Manipulation of micro- and nano- structures using organic materials has been of interest because this is a technology that fabricates complex pattern quickly and simply. Particularly, anisotropic-shaped organic molecules exhibit an intrisic interaction spontaneosly. And, they exhibit optical, electrical and mechanical anisotropy when they are controlled thier orientation, thus, these reasearch is actively being conducted in material science and industrial applications. In order to utilize these anisotropic organic molecules as functional materials, it is necessary to construct a specific structure and control orientation and alignment at the molecular level. Anisotropic organic molecules are sensitive to the external environment. And, it have been reported to control orientation through various methods such as surface treatment, photoalignment, confinement effect, magnetic field, and electric field. The method using an elecetric field has been known that the most effective and perfect technique for controlling anisotropic moleculues for a long time. In this thesis, we mainly discuss the controlling organic molecules by using an electric field and thier application for optics, particle patterning templates and mechanics. This thesis consists of four chapters. In the chapter 1, we briefly introduce the materials covered in this studies and the principle of controlling orientation with an electric field. In the second chapter, we demonstrate a platform to control the organic single molecules( liquid crystal) via intersection of electrodes and shows its optical applications. In chapter 3, we deals with the research on the fabrication of various liquid crystal structures through modulated system which the crossing of various electrodes and application of a complex electric field. In the last chapter, we researched of the formation of the patterned polymer thin film using liquid crystal network and thier mechanical application with same electric field technologies. we believe that these platform can manufacture as a three dimensional structure that could not perform using simple surface control methods, which can be used as an very innovative ways to construct various complex structures. Furthermore, from the viewpoint the technology, the system can be programmed by modulating the electrode design, electric field and material selection, which can broaden these system based applications.