Colloidal Crystallization and Transport in Stripes and Mazes

• Published in: Langmuir Vol. 21; no. 16; pp. 7518 - 7523
• Main Authors: Helseth, L. E, Backus, T, Johansen, T. H, Fischer, T. M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 02.08.2005
• Subjects: Biological Transport; Chemistry; Colloidal state and disperse state; Colloids - chemistry; Crystallization; Electromagnetic Fields; Exact sciences and technology; General and physical chemistry; Magnetics; Microscopy, Polarization; Models, Theoretical; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Protein Structure, Tertiary; Surface Properties; External field; Confinement; Patterning; Film; Crystallization; Static properties; Dynamic properties; Complexes; Colloid; Geometry; Particle; Liquid flow; Transport; Magnetic field
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la050827c

We study guided crystallization and transport of paramagnetic spheres on top of a magnetic film that arranges its domains into stripes or mazes. In the absence of liquid flow, the paramagnetic spheres are confined within the magnetic domains, and it is shown how the particles self-assemble into several interesting phases depending on the complexity of the domain patterns. We also find that colloids guided through a complex maze exhibit structured patterns that can be controlled by an external magnetic field. The results presented here could help us understand both static and dynamic properties of pattern formation in confined geometries of tunable complexity.