US Patent 7704320 Colloidal crystallization via applied fields

The methods provided use external fields such as light and electricity as a means of directing the crystallization of concentrated colloidal systems. Not only can nucleation be directed, crystal melting can be carefully controlled and light-induced crystal diffraction used as a means of directing light propagation. A number of factors play a significant role on the crystallization rate and location, including the intensity of the light field, the magnitude of the electric field, the colloid concentration, the colloid size, and the colloid composition. In varying these parameters, kinetics in these processes are extremely fast when compared to traditional colloidal crystallization approaches.