Wide-area Millimeter Motions
Applications such as silicon wafer alignment or
bio cell manipulations require fast and accurate
positioning within a few millimeters working
range. Widely used piezoelectric (PZT) actuators, however, have displacement ranges limited
to hundreds of micrometers.
such as “inchworm” clamping have been
introduced, but suffer from poor motion
repeatability, low payload and low speed. This has produced a challenge for the
precision engineering industry that has been met by the Singapore Institute of
Manufacturing Technology (SIMTech) with the introduction of its Flexure
based Electromagnetic Linear Actuator (FELA). Taking advantage of linear
elastic deflection, FELA’s flexure-based bearings provide frictionless motion.
The contact less nature of the electromagnetic-based Lorentz-force actuation
scheme helps ensure a linear relationship between input and output force. A
moving air-core coil configuration eliminates cogging effects cause by moving
magnet configurations, and the translation motion is governed by the deflection stiffness of the flexure-based bearings.
SIMTech has developed a series of FELAs that offers a traveling range of up
to 20 mm, unlimited positioning resolution, large force sensitivity of up to 120
N/A and fast actuating speed of at least 100 mm/sec.
◗ Singapore Institute of Manufacturing Technology (SIMTech),
Lower Emissions, More Power
By 2025, the automotive industry is
required to reduce
carbon dioxide (CO2)
emission by at least
30% while reducing
by a factor of three.
For decades, efforts to
standards like this
have depended on a
ing of Otto cycle dynamics in internal combustion engines and
development of ways to change emissions through exhaust
gas recirculation (EGR). Toward this goal, Dedicated-EGR
(D-EGR) by Southwest Research Institute (SwRI) goes to new
lengths by “dedicating” a separately controlled cylinder that
is allowed to run rich. SwRI engineers realized that fuel-rich
operation produces the chemical components necessary to cre-
ate cooled EGR (to reduce emissions) and reformate (carbon
monoxide and hydrogen), which improves efficiency. When
mixed with fresh air, the reformate is introduced into the other
cylinders, reducing knock and improving combustion.
By dedicating an individual cylinder to the production of
cooled EGR and reformate, EGR is separated from the tailpipe
exhaust. This allows the non-EGR cylinders to be operated at
a stoichiometric air-fuel ratio, simplifying after-treatment. In
addition, since the dedicated cylinder is directly connected to
the intake manifold, 100% of the reformate is captured and
returned to the engine.
◗ Southwest Research Institute, www.swri.org
Precision Stage for Nanoscale Studies
A deeper understanding of microstructure-me-chanical property correlations to processing conditions is sought by many industries. Hysitron Inc.’s
xSol High Temperature Stage is a new platform
that supports this effort, allowing researchers to
make high-resolution nanomechanical measurements over a broad temperature range.
The heating system consists of two high-power
core elements between which the sample is locat-
ed. This creates a micro-environmental chamber
in which both the sample and indenter tip are
kept at thermal equilibrium during indentation, a
crucial condition for reliable results. This micro-
chamber can also be filled with any reactive/shield
gas, providing uniform measurement conditions
without the necessity of complicated vacuum systems. No other available system
delivers precise temperature control over temperatures up to 800 C.
The low-drift stage has been specifically designed to enhance core nanoscale
characterization capabilities of Hysitron’s instrumentation. xSol can be paired with
in-situ scanning probe microscopy, nanoindentation, nanoscratch and nanowear.
Time-temperature-superposition studies of viscoelastic materials and prolonged,
elevated temperature creep experiments can be accurately and reliably performed.
◗ Hysitron Inc., www.hysitron.com