Transcript Design of Magnetic-Field Concentrators

Design of Magnetic-Field
Concentrators
Wednesday February 17th
Group: D
Mohammedzuned Desai
Areio Hashemi
Koji Hirota
Michael Wong
Outline
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Introduction
Applications
Objectives
Methods
Results
Conclusion
Future Work
Gantt Chart
References
Introduction
 What
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are Magnetic Tweezers (MT)?
Scientific instrument used for studying
molecular and cellular interactions
Ability to apply known forces on paramagnetic
particles using a magnetic field gradient
One of the most commonly used force
spectroscopy techniques
• Atomic Force Microscopy
• Optical Tweezers
Advantages of MT
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They do not have problems of sample heating
and photodamage that effects optical tweezers
 Magnetic forces are orthogonal to biological
interactions
 Offer the prospect of highly parallel singlemolecule measurements
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Hard to achieve with other single-molecule force
spectroscopy techniques
Applications
 The
magnet configurations are relatively
easy to assemble
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Combine force clamp properties with the
ability to impose rotation
Ideally suited for the study of DNA topology
and topoisomerases
Applications
http://www.biotec.tu-dresden.de/cms/fileadmin/research/biophysics/practical_handouts/magnetictweezers.pdf
Objectives
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Design and fabricate
magnetic tweezers
that is capable of
achieving forces up to
100pN
 Current design can
achieve 2pN
 Introduce illumination
for bright-field
transmission
microscopy
Ibrahim, George et al.
Methods
 Using
Finite Element Method Magnetics
(FEMM) to predict the geometries of the
magnet and that will produce the largest
possible field gradients
 Machine and assemble the design that will
produce the largest field gradients
 Calibrate the magnet so it is ready for data
acquisition
Rough Design
Methods
FEMM Methods
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Testing for material
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Testing for shape
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Iron
Mu metal
Flat
Tip
Flat Tip
Testing for optimum distance between two
magnets
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1mm
3mm
FEMM Results
¼ inch
1.5 inch
1/8 inch
Results (Material)
Iron
Mu Metal
|B| vs. length
|B|/dl vs. length
Results (Shape)
Tip
|B| vs. length
Flat Tip
|B|/dl vs. length
Results (Angle)
Double Magnet Tip 2mm Separation
Double Magnet Tip 3mm Separation
|B| vs. length
|B|/dl vs. length
Results (Distance)
Double Magnet FLAT 1mm Separation
Double Magnet FLAT 3mm Separation
|B| vs. length
|B|/dl vs. length
Conclusions
 Double
flat magnet from mu metal gave
best results
 If there is a sharp tip there is a huge
gradient at the tip but the working distance
is not feasible
 The distance between the two magnets
effects the gradient
Future Work
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Orders for the magnet cores have been placed
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When core arrives we can begin fabrication and
eventually develop the magnetic tweezers
Contacted a company regarding the coiling of
the magnets
 Putting the entire set up together
 Design a way for illumination of the sample
Progress Chart
References
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1) Neuman, Keri C, and Nagy, Attila. “Single-molecule force spectroscopy: optical
tweezers, magnetic tweezers and atomic force microscopy.” Nature Publishing Group
Vol. 5, NO. 6. June 2008.
2) Danilowicz, Claudia, Greefield, Derek and Prentiss, Mara. “Dissociation of LigandReceptor Complexes Using Magnetic Tweezers.” Analytical Chemistry Vol. 77, No.
10. 15 May. 2005.
3) Humphries; David E., Hong; Seok-Cheol, Cozzarelli; Linda A., Pollard; Martin J.,
Cozzarelli; Nicholas R. “Hybrid magnet devices fro molecule manipulation and small
scale high gradient-field applications”. United States Patent and Trademark Office, An
Agency of The United States Department of Commerce. <http://patft.uspto.gov>.
January 6, 2009.
4) Ibrahim, George; Lu, Jyann-Tyng; Peterson, Katie; Vu, Andrew; Gupta, Dr. Sharad;
Vullev, Dr. Valentine. “Magnetic Tweezers for Measuring Forces.” University of
California Riverside. Bioengineering Senior Design June 2009.
5) Startracks Medical, “Serves Business, Education, Government and Medical
Facilities Worldside.” American Solution. Startracks.org, Inc. Copyright 2003.
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