Browse Prior Art Database

Magnetostrictive Molecule Separator Chromatography

IP.com Disclosure Number: IPCOM000113467D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 82K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+3]

Abstract

Magnetostrictive Molecule Separator Chromatography (MMSC) is essentially a process for the separation of macromolecules according to their size, and therefore according to their molecular weight. Disclosed is a new method that is a useful addition to conventional separation methods which depend mainly on Gel Permeation Chromatography (GPC) using size exclusion. The disclosed method utilizes the property of magnetic materials called the magnetostriction effect. Magnetostriction is the expansion or contraction of a magnetic material under the influence of an external magnetic field. The magnetostriction constant, &lambda. is defined as the change in length Delta l per unit length, l; or Delta l / l and is usually given in parts per million (ppm).

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Magnetostrictive Molecule Separator Chromatography

      Magnetostrictive Molecule Separator Chromatography (MMSC) is
essentially a process for the separation of macromolecules according
to their size, and therefore according to their molecular weight.
Disclosed is a new method that is a useful addition to conventional
separation methods which depend mainly on Gel Permeation
Chromatography (GPC) using size exclusion.  The disclosed method
utilizes the property of magnetic materials called the
magnetostriction effect.  Magnetostriction is the expansion or
contraction of a magnetic material under the influence of an external
magnetic field.  The magnetostriction constant, &lambda.  is defined
as the change in length Delta l per unit length, l; or Delta l / l
and is usually given in parts per million (ppm).  Materials such as
Samarium Iron (SmFe2), Terfernol-D (TbDyFe), Cobalt-Iron (CoFe), and
Nickel (Ni), for example, have magnetostrictive constants that vary
from 2000 ppm down to 0.2 ppm, thus allowing  for expansions and
contractions of 100's of angstroms down to .01 angstroms, for a fixed
length of 5 microns, for example.

      The disclosed method utilities columns of a magnetostrictive
material that have been delineated using standard lithographic
processing techniques.  Photolithographic stencils are patterned with
a particular geometry to determine diameters, spacings, and lengths
of openings.  Using vapor deposition, or electroplating processes,
cylinders of the magnetostrictive material are deposited in these
openings.  This makes the process self aligning with respect to the
openings and the magnetostrictive plugs in the openings.  In
operation, a magnetic field is applied to open or close the openings.
If the field is applied in pulsed periodic fashion, it will cause the
magnetostrictive material to expand and relax, in effect, acting as a
pump.  Thus a cell can be fabricated for fractionation or size
selection.  One technique would be to use an etched silicon wafer as
a mask to deposit the columns through.  The deposition would stop a...