*******************************************************************************
Induction Based Fluidics (IBF)
IBF is a simple approach
to transport and to optionally treat liquids. In IBF, liquids are charged
with an electric field. Once energized, the liquids are launched to targets
of diverse type (human beings, MALDI targets, microtiter plates, microscope
slides, food, almost anything ) as they are dynamically directed to that
target, much like gas phase ions are directed in mass spectrometers. IBF can
be appended to many simple devices like syringes, pipettes, pumps of all
types, scientific instruments and other instruments.
In IBF, liquids are charged
and that action allows the performance of many simple, useful tasks
including flying nanoliter and microliter quantities of liquids, non-ouch to
targets of all types, such as humans, plants, and animals; microscope
slides; multiple-well plates; and scientific instruments. Through the
presentation of the physics of IBF, it has been shown that unlike
piezoelectric, sound, or any other technologies that are applied to
transport liquids, IBF technology employs an electric field that can 1)
kinetically launch drops to targets of all types, 2) dynamically direct the
liquids in flight (a very desirable, i.e., required, trait for small volumes
of liquids) to targets and details depending, and with the preferred options
3) count them on arrival. This simple technology has been called “elegant”
by the director of R&D of a major mass spectrometry firm.
The nanoliter regime offers a
number of obvious benefits over microliters and milliliters. These include
significant savings in expensive reagents; major reduction in human exposure
to toxic chemicals, allergens, agents, viruses, etc.; and greatly reduced
waste disposal costs. Because IBF has a massive dynamic range (μL to fL), it
has a substantial application space. It is a useful laboratory tool that has
wide application in, for example, simple sample dilution; MALDI biomarkers;
sample preparation; drug delivery; drug discovery; radiochemistry; homeland
security and defense applications; forensics; the sampling of human beings;
medical diagnostics sample preparation; and in the manufacture of unique
chemical and other entities, i.e., electrets. Finally, IBF also allows
non-touch dispensing in the microliter regime as well for more classical
assays, and also has interesting consumer applications.
To understand IBF, consider
the physics of a flowing laminar system. The liquid volume passing
through a tube is given by the Hagen Poiseuille equation. (IBF does not need
hybrid systems, and the flow can be purely electrokinetic, but that is
beyond the scope of this paper.) The volume of fluid (V) that flows
down a small-diameter capillary tube per unit of time (t), is
proportional to the fourth power of the radius of the rube (r), the pressure pushing
the fluid down the tube (P), and it is inversely proportional to
the length of the tube (l),
and the viscosity of the fluid (
).
Note V is linear in t.
V = ((π r4P)/8l)t
Now, if we grow a drop on a
capillary under these conditions, (or if we make a drop with our syringe) we
can then charge (q) the drop using an electric field E to
energize the drop. Upon charging, the liquid can experience the electric
force (qE) imparted by induction, similar to the manner in which gas
phase ions experience the qE force in mass spectrometers. Since
electric fields can be rapidly toggled on and off with high accuracy and
precision, the forces on the liquid drops can be changed rapidly and
accurately, as well.
F = qE
Because F is a vector,
we can direct the drop if we shape the field. Thus, for a charged drop with
initial value, q0, which depends on well-known solution
specifics, q can be defined as shown below where
q = q0
e(–t/λ)
t is the time and where λ = (ε0εr/κ), ε0 is the dielectric
constant of free space, εr is the relative permittivity, κ is the
solution conductivity.
Now, a charged liquid drop in
an electric field not only can experience the qE force, but
experiences different forces as well in the atmosphere in x, y,
and z space, depending on the specifics of the system, as stated
previously. Using standard, well-known physics, Newton’s 2nd law, we can
equate the forces (electric, drag, buoyancy, gravity, and coulombic) acting
on a drop to those acting in the direction, x, as:
Fx =
m (ax) = m (dvx/dt) = Felec
+ Fdrag + Fbuoy + Fgrav
+ Fcoul
Force equations can also be
written for the y and z coordinates; therefore, with accurate
model equations for Fy and Fz, we can actually calculate the
trajectories of the drops (distances of travel, d) of the drops at
any time, t, knowing that
Vx = dx/dt
Vy = dy/dt Vz = dx/dt,
and the initial position of
the drop, and that
V2 = Vx2
+ Vy2 + Vz2,
but that discussion is beyond
the scope of this discussion. So by using electric charge,
one can launch and direct liquids to targets, and this has massive
applications in a wide array of areas cited above and you an learn more at nanoliter.com. Plus
it can save reagents, reduce exposure and waste generation. Nanoliters are
not only very useful they are inherently “green”.
***************************************************
WHY NANOLITERS ?
Transporting
liquids is among the most frequently performed task in laboratories of all
types. This “function” is also performed to manufacture liquid products (e.g.,
drug solutions) and it is required at locales of health care. When small
quantities of liquids, e.g., nanoliters*(nLs), are employed instead of larger
volumes, it is obvious that
1. the cost of
reagents used can be greatly reduced,
2. the related
waste generation can be reduced as can
3. and human exposure to chemicals
can be eliminated.
4. PLUS one can do many new things
including non touch parallel LC, non touch parallel uL, nL and pL
dispensing, non touch parallel SPE and non touch parallel instrument
introduction.........
Applications of IBF and the Nanoliter Cool-Wave
Syringe & Systems.
Contact angle measurement, liquid handling for stem cell R&D, MALDI
and LC/MALDI including flash-speed quantitative work
making samples faster than you can analyze them, parallel LC, LC/MALDI and tissue MALDI. SPE,
LC and, CBRN, Microdosing Phase Zero Testing, TLC, DNA/RNA , forensics, sampling,
homeland
security, explosive/bioagent handling/testing, tagging, gluing, manufacturing of electronics
and optics, MS and DESI/DART standardization, sample
introduction, sample preparation, drug discovery, drug delivery, HLS
Detector QA @ Airports, Ports, etc. and more.
