Hard Magnetic Materials for MEMS Applications

Dempsey, Nora

doi:10.1007/978-0-387-85600-1_22

Cited by 18 publications

(8 citation statements)

References 54 publications

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“…They align according to the field lines from the array. A similar result is expected replacing the Ni seeds using micro-patterning of permanent magnets [15] without applying an external field.…”

Section: Magnetic Beads Close To Seeding Pointsupporting

confidence: 79%

Guided self-assembly of magnetic beads for biomedical applications

Gusenbauer

Nguyen

Reichel

et al. 2014

Physica B: Condensed Matter

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Micromagnetic beads are widely used in biomedical applications for cell separation, drug delivery, and hypothermia cancer treatment. Here we propose to use self-organized magnetic bead structures which accumulate on fixed magnetic seeding points to isolate circulating tumor cells. The analysis of circulating tumor cells is an emerging tool for cancer biology research and clinical cancer management including the detection, diagnosis and monitoring of cancer. Microfluidic chips for isolating circulating tumor cells use either affinity, size or density capturing methods. We combine multiphysics simulation techniques to understand the microscopic behavior of magnetic beads interacting with Nickel accumulation points used in lab-on-chip technologies. Our proposed chip technology offers the possibility to combine affinity and size capturing with special antibody-coated bead arrangements using a magnetic gradient field created by Neodymium Iron Boron permanent magnets. The multiscale simulation environment combines magnetic field computation, fluid dynamics and discrete particle dynamics

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Section: Magnetic Beads Close To Seeding Pointsupporting

confidence: 79%

Guided self-assembly of magnetic beads for biomedical applications

Gusenbauer

Nguyen

Reichel

et al. 2014

Physica B: Condensed Matter

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“…Down-scaling the size of magnets opens new opportunities for their use in micro-devices with applications in fields as diverse as telecommunications, energy management and bio-medicine. Sputtering combined with micro-patterning has been used to make fully dense magnets which are a micro-scale equivalent of sintered magnets and they may be isotropic or textured, depending on the deposition temperature [8]- [10]. Various techniques including casting and screen printing combined with photo-lithography have been used to make polymer bonded micro-magnets, but microscaled polymer bonded magnets reported to date are isotropic [10]- [13] In this article we present a process for the fabrication of anisotropic flexible bonded micro-magnets.…”

Section: Introductionmentioning

confidence: 99%

“…Sputtering combined with micro-patterning has been used to make fully dense magnets which are a micro-scale equivalent of sintered magnets and they may be isotropic or textured, depending on the deposition temperature [8]- [10]. Various techniques including casting and screen printing combined with photo-lithography have been used to make polymer bonded micro-magnets, but microscaled polymer bonded magnets reported to date are isotropic [10]- [13] In this article we present a process for the fabrication of anisotropic flexible bonded micro-magnets. Anisotropic powders were selected to maximise the magnetisation for a given volume fraction of magnetic material and to favour actuation through the use of magnetic torque [14], [15].…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Polymer-Bonded Flexible Anisotropic Micro-Magnet Arrays

et al. 2022

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Here we present a process for the fabrication of arrays of anisotropic flexible bonded micro-magnets attached to a transparent base. The micro-magnets are based on hard magnetic SmFeN or Sr-ferrite powders mixed with polydimethylsiloxane (PDMS). The size, shape and distribution of the micro-magnets are defined using a Si-mould fabricated by deep reactive ion etching (DRIE). The volume fraction of the magnetic powder was fixed at 30% while the thickness of the micro-magnets ranged from 50-300 μm and their in-plane dimensions from 20-400 µm. Powder alignment was achieved using a bulk NdFeB magnet. Arrays of micro-pillars of height 300 µm and width tapering from 300 µm at their base to 200 µm at their top were characterized using vibrating sample magnetometry (VSM) and Scanning Hall Probe Microscopy (SHPM) and the results of the latter were compared with analytical simulations. The homogeneous magnetic field produced by a 3-axis electromagnet was used to move the micro-pillars in a controlled fashion. The field induced in-plane displacement of the SmFeN-based pillars was more than three times greater than that of the Sr-ferrite-based ones, reaching 13 µm at the maximum applied field value of 100 mT.

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“…In the past decade, there has been substantial advancement in the synthesis of high-performance, thick-film magnetic materials intended for MEMS applications [1,2]. This advancement has spawned growing interest in the integration of microfabricated magnetic materials into functional microsystems devices.…”

Section: Introductionmentioning

confidence: 99%

“…This advancement has spawned growing interest in the integration of microfabricated magnetic materials into functional microsystems devices. However, the ongoing evolution of magnetic MEMS demands development of processes to microfabricate more complex, multipole magnetic structures to create spatially varying microscale magnetic field-patterns for microactuators, vibrational energy harvesters, lab-on-a-chip, and other applications [2].…”

Section: Introductionmentioning

confidence: 99%

Modeling of a Micromagnetic Imprinting Process

Oniku¹,

Garraud²,

Patterson³

et al. 2014

2014 Solid-State, Actuators, and Microsystems Workshop Technical Digest

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In this article, we present the magnetic modeling of a batchfabrication process to imprint microscale pole patterns in hardmagnetic thick films. The imprinting process enables the creation of complex magnetic field patterns from permanent magnetic layers. The selective magnetic imprinting and the resultant stray fields are modeled in a two-step process using COMSOL Multiphysics in conjunction with measured magnetic hysteresis behavior. The models are used to evaluate the process design space and to predict the resulting stray magnetic field distribution in a patterned, 10-µm-thick Co-Pt magnetic film.

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Hard Magnetic Materials for MEMS Applications

Cited by 18 publications

References 54 publications

Guided self-assembly of magnetic beads for biomedical applications

Guided self-assembly of magnetic beads for biomedical applications

Fabrication and Characterization of Polymer-Bonded Flexible Anisotropic Micro-Magnet Arrays

Modeling of a Micromagnetic Imprinting Process

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