Bulletin of the American Physical Society
APS March Meeting 2013
Volume 58, Number 1
Monday–Friday, March 18–22, 2013; Baltimore, Maryland
Session N10: Invited Session: Smart Magnetic Particles: On-Chip Transport, Assembly and Biomedical Applications |
Hide Abstracts |
Sponsoring Units: DCMP GMAG Chair: Valentyn Novosad, Argonne National Laboratory Room: 309 |
Wednesday, March 20, 2013 11:15AM - 11:51AM |
N10.00001: High-speed transport and magneto-mechanical resonant sensing of superparamagnetic microbeads using magnetic domain walls Invited Speaker: Elizabeth Rapoport Surface-functionalized superparamagnetic (SPM) microbeads are of great interest in biomedical research and diagnostic device engineering for tagging, manipulating, and detecting chemical and biological species in a fluid environment [1-5]. Recent work has shown that magnetic domain walls (DWs) can be used to shuttle individual SPM microbeads and magnetically tagged entities across the surface of a chip [1-5]. This talk will describe the dynamics of SPM microbead transport by nanotrack-guided DWs, and show how these coupled dynamics can be exploited for on-chip digital biosensing applications. Using curvilinear magnetic nanotracks, we demonstrate rapid transport of SPM microbeads at speeds approaching 1000 $\mu $m/s [3], and present a mechanism for selective transport at a junction that allows for the design of complex bead routing networks. We further demonstrate that a SPM bead trapped by a DW exhibits a distinct magneto-mechanical resonance that depends on its hydrodynamic characteristics in the host fluid [4, 5], and that this resonance can be used for robust size-based discrimination of commercial microbead populations. By embedding a spin-valve sensor within a DW transport conduit, we show that the resonance can be detected electrically and on-the-fly [5]. Thus, we demonstrate a complete set of essential bead handling functions, including capture, transport, identification, and release, required for an integrated lab-on-a-chip platform.\\[4pt] [1] G. Vieira et al., Phys. Rev. Lett. 103, 128101 (2009).\\[0pt] [2] M. Donolato et al., Lab Chip. 11, 2976--2983 (2011).\\[0pt] [3] E. Rapoport and G.S.D. Beach, Appl. Phys. Lett. 100, 082401 (2012).\\[0pt] [4] E. Rapoport and G.S.D. Beach, J. Appl. Phys. 111, 07B310 (2012).\\[0pt] [5] E. Rapoport, D. Montana, and G.S.D. Beach, Lab Chip. 12, 4433-4440 (2012) [Preview Abstract] |
Wednesday, March 20, 2013 11:51AM - 12:27PM |
N10.00002: Binary Colloidal Superlattices Assembled by Magnetic Fields Invited Speaker: Benjamin Yellen Colloidal particle superlattices represent a fascinating class of complex materials which in many cases have corollary structures at the atomic scale. These complex systems thus not only help elucidate the principles of materials assembly in nature, but further provide design criteria for fabrication of novel materials at the macroscopic scale. Methods for assembling colloidal particle superlattices include controlled drying, ionic interactions, and dipolar interactions. However, a general pathway for producing a wider variety of colloidal crystals remains a fundamental challenge. Here we demonstrate a versatile colloidal assembly system in which the design rules can be tuned to yield over 20 different pre-programmed lattice structures, including kagome, honeycomb, square tiles, as well as a variety of chain and ring configurations. We tune the crystal type by controlling the relative concentrations and interaction strengths between spherical superparamagnetic and diamagnetic particles. An external magnetic field causes like particles to repel and unlike particles to attract. The combination of our experimental observations with potential energy calculations of various lattice structures suggest that the lowest energy lattice configuration is determined by two parameters, namely the dipole moment and relative concentration of each particle type. [Preview Abstract] |
Wednesday, March 20, 2013 12:27PM - 1:03PM |
N10.00003: Magnetic microstructures for regulating Brownian motion Invited Speaker: Ratnasingham Sooryakumar Nature has proven that it is possible to engineer complex nanoscale machines in the presence of thermal fluctuations. These biological complexes, which harness random thermal energy to provide functionality, yield a framework to develop related artificial, i.e., nonbiological, phenomena and devices. A major challenge to achieving positional control of fluid-borne submicron sized objects is regulating their Brownian fluctuations. In this talk a magnetic-field-based trap that regulates the thermal fluctuations of superparamagnetic beads in suspension will be presented. Local domain-wall fields originating from patterned magnetic wires, whose strength and profile are tuned by weak external fields, enable bead trajectories within the trap to be managed and easily varied between strong confinements and delocalized spatial excursions. Moreover, the frequency spectrum of the trapped bead responds to fields as a power-law function with a tunable, non-integer exponent. When extended to a cluster of particles, the trapping landscape preferentially stabilizes them into formations of 5-fold symmetry, while their Brownian fluctuations result in frequent transitions between different cluster configurations. The quantitative understanding of the Brownian dynamics together with the ability to tune the extent of the fluctuations enables the wire-based platform to serve as a model system to investigate the competition between random and deterministic forces. [Preview Abstract] |
Wednesday, March 20, 2013 1:03PM - 1:39PM |
N10.00004: Smart Magnetic Materials for Controlling Cell Fate Invited Speaker: Elina Vitol Toxicity of cancer chemotherapy, often resulting in failure of even healthy organs, represents one of the most vivid and still unavoidable outcomes of traditional medical approaches to treating a disease. The lack of specificity remains a fundamental obstacle in performing targeted treatment which should ideally affect only the particular cells in a human body. Nanotechnology has recently enabled the possibility to create materials comparable in sizes with cells and subcellular structures opening the opportunities for affecting intracellular processes on the level unattainable by macroscopic techniques. [1-2] Magnetic nanomaterials are especially promising for applications in life sciences due to their bi-functional behavior. On the one hand side, they are inherently stimuli-responsive and their properties can be controlled and modulated remotely. On the other hand, these materials themselves can be used for applying controlled stimulus to a cell thus changing its function and even inducing cell death [3]. For biological applications, such multifaceted functionality opens the unique opportunity to modulate cell behavior by interfacing it with magnetic material. Historically, chemically synthesized superparamagnetic iron oxide particles have been widely studied for biological applications such as magnetic separation, targeting, MRI contrast enhancement and magnetically induced heating [1,4]. At the same time, there is a growing interest to magnetic materials created by physical fabrication methods which allow for realization of very complex structures in terms of geometry and composition [5]. In this talk, both types of materials will be discussed. Thus, thermo-responsive magnetic micelles were used as nanocontainers for magnetically guided drug delivery and release triggered by heating in the RF frequency a.c. magnetic field. The microfabricated biofunctionalized microdisks targeted to the cancer cells were employed for mechanical stimulation of cell membrane due to oscillation of the disks in the low frequency (10-20 Hz) a.c. magnetic field, resulting in redistribution of free intracellular calcium and subsequent triggering of apoptosis - programmed cell suicide [3,5]. The details of mechanisms by which the cell responds to the stimulus applied by magnetic particles will be discussed.\\[4pt] [1] E. A. Rozhkova, Nanoscale Materials for Tackling Brain Cancer: Recent Progress and Outlook. Advanced Materials, 2011. 23(24): p. H136-H150; [2] E. A. Vitol, Z. Orynbayeva, G. Friedman, Y. Gogotsi, Nanoprobes for intracellular and single cell surface-enhanced Raman spectroscopy, J. Raman Spectrosc., (2012) Accepted, Available online: doi: 10.1002/jrs.3100; [3] D.-H. Kim, E.A. Rozhkova, I.V. Ulasov, S. D. Bader, T. Rajh, M. S. Lesniak, V. Novosad, Biofunctionalized magnetic-vortex microdiscs for targeted cancer-cell destruction. Nature Materials 2009, 9, (2), 165-171; [4] J. Dobson, Remote control of cellular behaviour with magnetic nanoparticles. Nature Nanotechnology, 2008. 3(3): p. 139-143; [5] E. A. Vitol, V. Novosad, E. A. Rozhkova, Microfabricated magnetic structures for future medicine: from sensors to cell actuators, Nanomedicine, 2012 (In press). [Preview Abstract] |
Wednesday, March 20, 2013 1:39PM - 2:15PM |
N10.00005: Biomedical Applications of Magnetic Nanoparticles: Delivering Genes and Remote Control of Cells Invited Speaker: Jon Dobson The use of magnetic micro- and nanoparticles for biomedical applications was first proposed in the 1920s as a way to measure the rehological properties of the cell's cytoplasm. Since that time, magnetic micro- and nanoparticle synthesis, coating and bio-functionalization have advanced significantly, as have the applications for these particles. Magnetic micro- and nanoparticles are now used in a variety of biomedical techniques such as targeted drug delivery, MRI contrast enhancement, gene transfection, immno-assay and cell sorting. More recently, magnetic micro- and nanoparticles have been used to investigate and manipulate cellular processes both \textit{in vitro} and \textit{in vivo}. This talk will focus on magnetic nanoparticle targeting to and actuation of cell surface receptors to control cell signaling cascades to control cell behavior. This technology has applications in disease therapy, cell engineering and regenerative medicine. The use of magnetic nanoparticles and oscillating magnet arrays for enhanced gene delivery will also be discussed. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700