Project 7

Assessing Three dimensional Electrokinetic Colloid self-assembly

(Prof. stuart williams, ME)

Colloidal self-assembly methods create ordered structures from an otherwise disordered system without external direction. A reliable self-assembly method that enables precise and rapid placement of nanoparticles will provide an extremely valuable tool for the development of novel materials. This project will introduce the student to a multidisciplinary technique that couples fluid dynamics, heat transfer, optics, and electrokinetics for the self-assembly of colloids (Figure 1) termed rapid electrokinetic patterning (REP) [1]. Our lab has demonstrated patterning of these aggregations with a scanning laser [2].

For this project, the student will investigate the ability to manipulate and pattern colloids. Colloid aggregation is a function of AC frequency, AC voltage, fluid conductivity, and particle diameter. Patterns are defined through a combination of electrohydrodynamics and particle electrokinetics. A confocal microscope will be used to look at the three-dimensional structure of aggregations. Crystallinity and interactions will be assessed as a function of the applied field (AC frequency, voltage). 

References

[1] Williams, S. J., Kumar, A., Green, N. G., Wereley, S. T., Journal of Micromechanics and Microengineering 2010, 20.

[2] Velasco, V., Work, J., A. H., Williams, S. J., Electrophoresis 2012, 33, 1-7.