(634d) Directed Microparticle Assembly Using Magnetic Fields

We seek to create complex self-assembled structures from magnetic microparticles by combining both paramagnetic and nonmagnetic particles in ferrofluid. This leads to multiple types of magnetic interactions that differ depending on their direction with respect to the externally applied magnetic field. We are interested in utilizing this system to form more complex structures than the linear chains that typically form with paramagnetic particles using dipolar interactions. By tuning the magnetic susceptibility of the ferrofluid we are able to alter the strength of the magnetic interaction between each type of particle independently and thus create assemblies with different structural morphologies.

In this talk, we outline our attempts to understand the growth processes occurring in these structures. These structures are characterized by examining the power law exponents governing their growth as a function of the dimensionless interaction strength. Additionally, their overall shape is examined by determining their fractal dimension. We hope to use these observations to create a system with the ability to grow predictable particle clusters in more than one dimension.