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Shubham Bhat
Advisor: Timothy Kurzweg, Ph.D.
Abstract:
Manipulation of magnetic objects in fluids is a promising technology for many applications including targeted drug delivery, sorting and analysis of biological objects, and self-assembly of microsystems. Using magnetic gradients, limited aspects of assembly and manipulation of magnetic and non-magnetic micro-particles have been recently demonstrated experimentally. However, the main challenge with these gradient-based systems is that it is difficult to obtain the sufficiently large gradients required in many practical applications. To meet this end, we provide a solution to this problem by showing that, manipulation and controlled locomotion of multiple magnetic objects in fluids is indeed possible by using only a uniform external magnetic field of time-varying magnitude and direction.
In this research, I formulate the simplest system of interest consisting of two spherical magnetic particles of different diameters. Particles in this formalism are treated as linearly magnetizable dipoles. The evolution of their magnetic, hydro-dynamic interactions and positions representing the internal state of the system is described by a set of coupled first-order differential equations, with the external uniform magnetic field viewed as the input to the system. A non-linear controller is employed which helps maintain boundedness between the centers of the two particles and produces net displacement of the system. Further, a corrective feedback controller is designed in order to regulate the desired trajectory from small perturbations.
Using this formalism, I demonstrate theoretically in simulation and soon experimentally in hardware, a remarkable result that, in fact, it is possible for two magnetic particles of unequal diameters to swim in fluids by synchronizing their movements through interactions.
Friday, June 14th at 10:30 a.m.
Bossone 303
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