Design of Magnetic-Field Design of Magnetic-Field ConcentratorsConcentrators

Wednesday February 17thWednesday February 17thGroup: DGroup: D

Mohammedzuned DesaiMohammedzuned DesaiAreio HashemiAreio Hashemi

Koji HirotaKoji HirotaMichael WongMichael Wong

OutlineOutline IntroductionIntroduction ApplicationsApplications ObjectivesObjectives MethodsMethods ResultsResults ConclusionConclusion Future WorkFuture Work Gantt ChartGantt Chart ReferencesReferences

IntroductionIntroduction

What are Magnetic Tweezers (MT)?What are Magnetic Tweezers (MT)? Scientific instrument used for studying Scientific instrument used for studying

molecular and cellular interactionsmolecular and cellular interactions Ability to apply known forces on paramagnetic Ability to apply known forces on paramagnetic

particles using a magnetic field gradientparticles using a magnetic field gradient One of the most commonly used force One of the most commonly used force

spectroscopy techniquesspectroscopy techniques• Atomic Force MicroscopyAtomic Force Microscopy• Optical TweezersOptical Tweezers

Advantages of MTAdvantages of MT

They do not have problems of sample heating They do not have problems of sample heating and photodamage that effects optical tweezersand photodamage that effects optical tweezers

Magnetic forces are orthogonal to biological Magnetic forces are orthogonal to biological interactionsinteractions

Offer the prospect of highly parallel single-Offer the prospect of highly parallel single-molecule measurements molecule measurements Hard to achieve with other single-molecule force Hard to achieve with other single-molecule force

spectroscopy techniquesspectroscopy techniques

ApplicationsApplications

The magnet configurations are relatively The magnet configurations are relatively easy to assembleeasy to assemble Combine force clamp properties with the Combine force clamp properties with the

ability to impose rotationability to impose rotation Ideally suited for the study of DNA topology Ideally suited for the study of DNA topology

and topoisomerasesand topoisomerases

ApplicationsApplications

http://www.biotec.tu-dresden.de/cms/fileadmin/research/biophysics/practical_handouts/magnetictweezers.pdf

ObjectivesObjectives

Design and fabricate Design and fabricate magnetic tweezers that magnetic tweezers that is capable of achieving is capable of achieving forces up to 100pNforces up to 100pN Current design can Current design can

achieve 2pNachieve 2pN Introduce illumination Introduce illumination

for bright-field for bright-field transmission transmission microscopymicroscopy

Ibrahim, George et al.

MethodsMethods

Using Finite Element Method Magnetics Using Finite Element Method Magnetics (FEMM) to predict the geometries of the (FEMM) to predict the geometries of the magnet and that will produce the largest magnet and that will produce the largest possible field gradients possible field gradients

Machine and assemble the design that will Machine and assemble the design that will produce the largest field gradients produce the largest field gradients

Calibrate the magnet so it is ready for data Calibrate the magnet so it is ready for data acquisitionacquisition

Rough DesignRough Design

MethodsMethods

FEMM MethodsFEMM Methods Testing for materialTesting for material

IronIron Mu metal Mu metal

Testing for shapeTesting for shape FlatFlat TipTip Flat TipFlat Tip

Testing for optimum distance between two Testing for optimum distance between two magnetsmagnets 11mmmm 33mmmm

FEMM ResultsFEMM Results

¼ inch

1.5 inch

1/8 inch

Results (Material)Results (Material)

Iron

Mu Metal

|B| vs. length

|B|/dl vs. length

Results (Shape)Results (Shape)

Tip

Flat Tip

|B| vs. length

|B|/dl vs. length

Results (Angle) Results (Angle)

Double Magnet Tip 2mm Separation

Double Magnet Tip 3mm Separation

|B| vs. length

|B|/dl vs. length

Results (Distance)Results (Distance)

Double Magnet FLAT 1mm Separation

Double Magnet FLAT 3mm Separation

|B| vs. length

|B|/dl vs. length

ConclusionsConclusions

Double flat magnet from mu metal gave Double flat magnet from mu metal gave best resultsbest results

If there is a sharp tip there is a huge If there is a sharp tip there is a huge gradient at the tip but the working distance gradient at the tip but the working distance is not feasibleis not feasible

The distance between the two magnets The distance between the two magnets effects the gradienteffects the gradient

Future WorkFuture Work

Orders for the magnet cores have been placedOrders for the magnet cores have been placed When core arrives we can begin fabrication and When core arrives we can begin fabrication and

eventually develop the magnetic tweezerseventually develop the magnetic tweezers

Contacted a company regarding the coiling of Contacted a company regarding the coiling of the magnetsthe magnets

Putting the entire set up togetherPutting the entire set up together Design a way for illumination of the sampleDesign a way for illumination of the sample

Progress ChartProgress Chart

ReferencesReferences 1) Neuman, Keri C, and Nagy, Attila. “Single-molecule force spectroscopy: optical 1) Neuman, Keri C, and Nagy, Attila. “Single-molecule force spectroscopy: optical

tweezers, magnetic tweezers and atomic force microscopy.” tweezers, magnetic tweezers and atomic force microscopy.” Nature Publishing GroupNature Publishing Group Vol. 5, NO. 6. June 2008.Vol. 5, NO. 6. June 2008.

2) Danilowicz, Claudia, Greefield, Derek and Prentiss, Mara. “Dissociation of Ligand-2) Danilowicz, Claudia, Greefield, Derek and Prentiss, Mara. “Dissociation of Ligand-Receptor Complexes Using Magnetic Tweezers.” Receptor Complexes Using Magnetic Tweezers.” Analytical ChemistryAnalytical Chemistry Vol. 77, No. Vol. 77, No. 10. 15 May. 2005.10. 15 May. 2005.

3) Humphries; David E., Hong; Seok-Cheol, Cozzarelli; Linda A., Pollard; Martin J., 3) Humphries; David E., Hong; Seok-Cheol, Cozzarelli; Linda A., Pollard; Martin J., Cozzarelli; Nicholas R. “Hybrid magnet devices fro molecule manipulation and small Cozzarelli; Nicholas R. “Hybrid magnet devices fro molecule manipulation and small scale high gradient-field applications”. United States Patent and Trademark Office, An scale high gradient-field applications”. United States Patent and Trademark Office, An Agency of The United States Department of Commerce. <http://patft.uspto.gov>. Agency of The United States Department of Commerce. <http://patft.uspto.gov>. January 6, 2009. January 6, 2009.

4) Ibrahim, George; Lu, Jyann-Tyng; Peterson, Katie; Vu, Andrew; Gupta, Dr. Sharad; 4) Ibrahim, George; Lu, Jyann-Tyng; Peterson, Katie; Vu, Andrew; Gupta, Dr. Sharad; Vullev, Dr. Valentine. “Magnetic Tweezers for Measuring Forces.” University of Vullev, Dr. Valentine. “Magnetic Tweezers for Measuring Forces.” University of California Riverside. Bioengineering Senior Design June 2009.California Riverside. Bioengineering Senior Design June 2009.

5) Startracks Medical, “Serves Business, Education, Government and Medical 5) Startracks Medical, “Serves Business, Education, Government and Medical Facilities Worldside.” American Solution. Startracks.org, Inc. CopyrightFacilities Worldside.” American Solution. Startracks.org, Inc. Copyright 2003. 2003. <http://images.google.com/imgres?imgurl=http://www.startracksmedical.com/<http://images.google.com/imgres?imgurl=http://www.startracksmedical.com/supplies/invertedmicroscope.jpg&imgrefurl=http://www.startracksmedical.com/supplies/invertedmicroscope.jpg&imgrefurl=http://www.startracksmedical.com/supplies.html&usg=__butCY2zWJa7nAkwkjiPxX_mFy0=&h=450&w=450&sz=24&hl=supplies.html&usg=__butCY2zWJa7nAkwkjiPxX_mFy0=&h=450&w=450&sz=24&hl=en&start=2&um=1&tbnid=XH6gnQuJLS7bRM:&tbnh=127&tbnw=127&prev=/imagesen&start=2&um=1&tbnid=XH6gnQuJLS7bRM:&tbnh=127&tbnw=127&prev=/images%3Fq%3Dinverted%2Bmicroscope%26hl%3Den%26sa%3DN%26um%3D1>%3Fq%3Dinverted%2Bmicroscope%26hl%3Den%26sa%3DN%26um%3D1>