Lagrangian Modeling of the Magnetization and the Magnetic Torque on Assembled Soft-Magnetic MEMS Devices for Fast Computation and Analysis

AbstractThis paper reports a novel fabrication process enabling the integration of mechanical MEMS devices with thick amorphous soft magnetic field concentrators. The integration process combines silicon on insulator technology for the MEMS device fabrication and epoxy-resin-based attachment of 18-µm-thick amorphous soft magnetic ribbons followed by a wet chemical structuring process. The fabrication process is reported on the basis of a field-concentrator-based resonant magnetic sensor combining an electrostatically driven micromechanical resonator and a planar magnetic field concentrator with two narrow gaps. For realization of the concentrator gaps, the integration process is extended by micro-patterning of the soft magnetic ribbons via UV-laser ablation using an excimer laser system. The characterization of the fabricated resonant magnetic sensor using a stroboscopic video microscope for in-plane motion measurement shows a high sensitivity of 390 kHz/T at a magnetic flux density of 158 µT.

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Modeling magnetic torque and force for controlled manipulation of soft-magnetic bodies

2007 IEEE/ASME international conference on advanced intelligent mechatronics ◽

10.1109/aim.2007.4412546 ◽

2007 ◽

Cited By ~ 4

Author(s):

Jake J. Abbott ◽

Olgac Ergeneman ◽

Michael P. Kummer ◽

Ann M. Hirt ◽

Bradley J. Nelson

Keyword(s):

Magnetic Torque ◽

Soft Magnetic

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Fully Lagrangian Modeling of Dynamics of MEMS With Thin Beams—Part II: Damped Vibrations

Journal of Applied Mechanics ◽

10.1115/1.3086786 ◽

2009 ◽

Vol 76 (5) ◽

Cited By ~ 4

Author(s):

Ranajay Ghosh ◽

Subrata Mukherjee

Keyword(s):

Electric Field ◽

Stokes Flow ◽

Elastic Field ◽

Companion Paper ◽

Lagrangian Description ◽

Mems Devices ◽

Lagrangian Modeling ◽

Modeling Of Dynamics ◽

Thin Beams ◽

Element Method

Micro-electro-mechanical systems (MEMS) often use beam or plate shaped conductors that are very thin with h/L≈O(10−2–10−3) (in terms of the thickness h and length L of a beam or side of a square plate). A companion paper (Ghosh and Mukherjee, 2009, “Fully Lagrangian Modeling of Dynamics of MEMS With Thin Beams—Part I: Undamped Vibrations,” ASME J. Appl. Mech., 76, p. 051007) addresses the coupled electromechanical problem of MEMS devices composed of thin beams. A new boundary element method (BEM) is coupled with the finite element method (FEM) by Ghosh and Mukherjee, and undamped vibrations are addressed there. The effect of damping due to the surrounding fluid modeled as Stokes flow is included in the present paper. Here, the elastic field modeled by the FEM is coupled with the applied electric field and the fluid field, both modeled by the BEM. As for the electric field, the BEM is adapted to efficiently handle narrow gaps between thin beams for the Stokes flow problem. The coupling of the various fields is carried out using a Newton scheme based on a Lagrangian description of the various domains. Numerical results are presented for damped vibrations of MEMS beams.

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Modeling Magnetic Torque and Force for Controlled Manipulation of Soft-Magnetic Bodies

IEEE Transactions on Robotics ◽

10.1109/tro.2007.910775 ◽

2007 ◽

Vol 23 (6) ◽

pp. 1247-1252 ◽

Cited By ~ 201

Author(s):

Jake J. Abbott ◽

OlgaÇ Ergeneman ◽

Michael P. Kummer ◽

Ann M. Hirt ◽

Bradley J. Nelson

Keyword(s):

Magnetic Torque ◽

Soft Magnetic

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Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105916 ◽

1988 ◽

Vol 46 ◽

pp. 770-771

Author(s):

June D. Kim

Keyword(s):

Electron Microscopy ◽

Magnetic Properties ◽

Ternary Phase Diagram ◽

Vertical Tube ◽

Vacuum Induction Melting ◽

Induction Melting ◽

Soft Magnetic ◽

Quenching Temperature ◽

Thin Foils ◽

Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

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