Redondo Beach, California - July 25, 2007 –Intelligent discrimination of target particles of interest from a complex liquid
matrix is of critical interest in biodefense and homeland security applications. A
miniaturized system for dielectrophoresis (DEP) based particle and cell sorting is
being developed by CFD Research Corporation (CFDRC), Huntsville, AL.
Important for the realization of miniaturized and multiplexed systems is the
requirement for laminar flow and the movement of particles/cells in response to
an electric field. Such a system requires the use of micron-sized flow channels
with a very small electrode gap (10 – 50 microns) to obtain the electric field
strengths necessary to effect particle sorting at nominal values of the applied
voltage.
 To achieve the design requirements, ALine used
a laminate fabrication approach to design a
simple flowcell that allowed the transparent
patterned ITO electrodes on glass to be aligned
and bonded directly to the top and bottom of the
flow channel, as shown in Figure 1. Using our
approach dozens of prototypes, which were
supported in a custom fabricated acrylic holder
allowing electrical connections and easy
observation under a microscope, permitted direct
observation of fluorescently tagged particles.
“The first generation prototypes successfully
demonstrated the proof of concept, which lead to
Phase II funding for our program”, remarked Dr. Kapil Pant, Manager,
Biodefense Technology, at CFDRC. “We appreciate ALine’s responsiveness and ability to bring together cutting-edge fabrication techniques to produce high quality
functional prototypes.”
Dr. Levine, founder of ALine concurred, “Our ability to create laser patterned
electrodes, without the hassle of the traditional masking and wet chemical
methods, provided a cost effective and flexible means for incorporating the
complex electrode design required. In addition, alignment and direct bonding to
the top and bottom of the flowcell using a bio compatible pressure sensitive
adhesive (PSA), offered a convenient, approach for creating the channel heights
needed.”
The laser patterned circuits had features separated by 40 microns, with a
minimum feature size of 10 microns possible. The patterning process requires
no tooling. Because they are bonded to the flowcell with a PSA, they can be
removed and re-used in a new set of flowcells.
In the absence of applied electric field (DEP OFF), the bulk of the particles
continue along the main channel with some entering the side channel due to the
hydrodynamic flow split. However, upon energizing the electrodes (DEP ON), all
of the particles are deflected into the side channel. Additional information on
CFDRC’s programs in the area of micro- and nano-systems can be found by
clicking here.
Gold interdigitated electrodes have also been successfully developed which were
bonded to a flowcell using biocompatible PSA s. Patterned gold or ITO coated
materials can be either glass or plastic and are transparent for viewing under a
microscope.
A simple approach for incorporating an electrode is to replace it with one of the
window film materials in our standard product, the FluoroVette. This allows spectroscopic observation of changes in the sample cell using a standard
spectrophotometer or fluorimeter.
The versatility of our laminate fabrication approach and the ability to incorporate
complex patterned circuits and electrodes, heaters, valves, and porous
membranes, offers life science researchers and product developers a valuable
tool box for the realization of novel bio micro fluidic products.
ALine is a leading supplier of high functionality bio micro solutions to biological,
healthcare, chemical, environmental, instrumentation and research markets.
Press Contact:
Dr. Leanna Levine
Email: llevine@alineinc.com
Phone: 310-707-8575
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