Self-assembly in nematic colloids

Abstract

The ability to generate regular spatial arrangements of particles on different length scales is one of the central issues of the bottom-up approach in nanotechnology. Current techniques rely on single atom or molecule manipulation by the STM, colloidal particle manipulation by laser or optoelectronic tweezers, microfluidics, optofluidics, micromanipulation and classical lithography. Of particular interest is self-assembly, where the pre-determined spatial arrangements of particles, such as 3D photonic crystals, could be realized spontaneously. Dispersions of particles in liquid crystals show several novel classes of anisotropic forces between inclusions, which result in an amazing diversity of self-assembled patterns, such as linear chains and 2D photonic crystals of microspheres. The forces between the particles in nematic colloids are extremely strong and long-range, resulting in several thousand times stronger binding compared to the binding in water based colloids. The mechanisms of self-assembly in nematic colloids are discussed, showing this is a novel paradigm in colloidal science, which can lead to new approaches in colloidal self-assembly for photonic devices.