for the high precision,
high speed Dispensation, the SMLD series sub micro liter dispensing valves are used in
all Techelan's TEDA type dispensers and are also sold separately.
guarantee the most accurate dispensation down
to 20 nl with CVs of <5% with operating frequency exceeding 2000
dispensations per second.
The SMLD type valves and drivers are available
type valves are miniature, high precision, micro-valves
fabricated in Switzerland to the highest European standards. They employ
Sapphire and Ruby materials to form unique fluid controlling surfaces. These valves are individually
QC tested and adjusted to assure the highest accuracy and reproducibility. The
reliability of these valves is expected to exceed 100,000,000 dispensations
under normal dispensing conditions.
A sapphire valve seat with the ruby ball
(hard on hard surface interface) assures a well-defined, precise
dispensation with minimal adhesion, retention and accumulation of reagents.
The valve orifice is specially designed to reduce flow turbulence and
eliminate formation of satellite droplets, adding to the overall accuracy of the
dispensing process. Micro valve dimensions enable their use in tight linear or
matrix arrays. An example of 8 x 12 matrix on a standard Micro-titer plate
format (3.4" x 5") with 9 mm spacing using SMLD 100
valve is shown on the right-bottom sketch.
It is highly recommended to pre-filter (20-50um) any material upstream of
the micro-valve to minimize clogging.
The general layout of the SMLD 100 type valve is
(Click to Start/Enlarge)
The SMLD 300 type valves are featuring a unique modular construction,
where the fluid valve can be separated (extracted from) the holding shell
and/or activating coil, which serves as a holding shell. This provides a convenient option for
"on the fly" valve replacement and service.
Both SMLD 100 and SMLD 300 valves can be assembled into linear 4.5MM
center to center arrays. Valves can have both barbed or straight tube
intake connection for the fluidic interface.
Optional terminating attachments enable valves to be
interfaced with various fluidic systems or to be positioned "in-line".
Special holding fixtures enable an easy positioning,
holding or replacement of valves.
OPTIONS and APPLICATIONS:
Valves are activated
by a short 12 to 24 VDC pulse (0.14 to 0.09 msec), followed by a 3 VDC (RMS) holding
voltage (See Drivers). Valves closure is partially dependent on liquid viscosity and
pressure and can take up to 0.15 msecís.
Recommended operating pressure is up to 30 PSI, although valves were
successfully tested up to 100 PSI and higher.
Valve drivers, which support the step function of the applied
voltage are available separately.
Both the dispensation pressure and time affect the
dispensation pattern and volume. Different pressures and timing should be
1. "Soft" surface retained dispensation without bouncing
2. "Hard" stream dispensation for agitation, re-suspension,
deep penetration, etc
3. Elimination of "satellite" droplets.
4. Forced atomization (spray-droplets).
Various examples are shown in associated
Please contact us for additional information.