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Three Dimensional Aggregation of Magnetic Particles

Pai, Alex and Ho, Dimitar and Hajimiri, Ali (2018) Three Dimensional Aggregation of Magnetic Particles. . (Unpublished)

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Magnetic drug delivery is a promising therapeutic because of magnetic fields' ability to permeate unperturbed in human tissue. One of the long-standing challenges in magnetic drug delivery is the inability to generate 3D aggregation non-invasively within the interior of the body. Earnshaw's theorem, which proves the impossibility of creating an energetic minimum in a curl-free and divergence-free field such as a magnetic field. However, one of the assumptions of Earnshaw's theorem is a static field. Here we show that it is possible to utilize a dynamically changing field and a dissipative force such as the drag, which is generally present, to create a stable aggregation point for magnetic particles. We also introduce a theoretical framework for designing the suitable magnetic fields for controlling a given magnetic particle in a particular fluid. This framework enables accurate determination of the necessary parameters for aggregation across a wide variety of magnetic particles and across multiple biologically-relevant fluids. By coating magnetic particles with desired therapeutic agents or attaching them to cells, a new class of treatment methodologies can be created in therapies such as targeted drug delivery and cell-based therapies. By dynamically changing the aggregation point, agents can also be guided along a particular path in the body. This technique of using dissipative forces to create a stable 3D aggregation point for particles could possibly be extended to a broad range of applications such as microscopic and macroscopic manipulation, robotics, guided self-assembly, magnetic plasma confinement, tissue engineering, and ion traps for quantum computers.

Item Type:Report or Paper (Discussion Paper)
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URLURL TypeDescription Paper
Hajimiri, Ali0000-0001-6736-8019
Additional Information:The authors would like to thank Michelle Wang for her indefatigable and unflappable efforts in helping to establish an experimental demonstration of aggregation. Alex White provided us with creative debugging and passionate spirits in our 11th hour. The authors would also like to thank Brian Hong for his efforts in perusing and proofreading this manuscript. Last but not least, the authors would like to thank Reza Fatemi for extremely helpful technical discussions. Competing Interests: The authors declare that they have no competing financial interests.
Record Number:CaltechAUTHORS:20180817-160152672
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:88942
Deposited By: George Porter
Deposited On:20 Aug 2018 14:34
Last Modified:09 Mar 2020 13:18

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