January 2018 9
EVENTS, ADVANCES, AND NEWS
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Optical Tweezers to Replace ’Bots
Robots are highly effective in assembly operations
ranging from automotive parts to circuit boards, but what
do you do when components are too small to be handled
by man or machine?
Well, a team of researchers at the University of
Glasgow, Scotland have come up with a new light-based
micromanipulation technique that they speculate may be
used someday [i.e., probably never] as a cheaper way to
mass-produce electronic components for smartphones,
computers, Io T equipment, and other compact devices.
The process involves the use of optical traps which
use light to hold and move small objects. Optical trapping
has been less than successful in earlier attempts, as
the objects must be suspended in liquid for the
“optoelectronic tweezers” to work. The problem
is that the liquid must be removed without
disturbing the assembled components, which
has been more or less impossible. However,
Prof. Shuailong Zhang, a member of the research
group, discovered that freeze-drying does the trick
According to Zhang, “Optoelectronic
tweezers are cost-effective and allow parallel
micromanipulation of particles. In principle,
we can move 10,000 beads at the same time.
Combining this with our freeze-drying approach
creates a very inexpensive platform that is suitable
for use in mass production. Using our method,
we can move solder beads measuring from the
nanometer range up to about 150 microns.
We have been able to move objects that are over 150
microns, but it’s more challenging because, as the size of
the object increases, the frictional force also increases.”
“We are now using a computer to generate the light
pattern to move the beads, but we are working on an
app that would allow a tablet or smartphone to be used
instead,” Zhang noted. “This could allow someone to sit
away from the system and use their finger to control the
movements of the particles, for example.” ▲
More Accuracy, Less Battery Drain
As Wyatt Earp once observed, “Fast is fine, but
accuracy is everything.” He was no doubt referring to his
Colt . 45, but the principle applies to GPS equipment as
In all likelihood, your smartphone is equipped with
a GPS device that allows for the usual navigation apps,
as well as a slew of location-based services (LBSs) such
as vehicle tracking, weather, object search, medical
applications, and so forth. (It also has Wi-Fi and cellular
positioning, but that’s another matter.)
Until now, your LBS apps have relied on single-frequency transmissions from Global Navigation Satellite
Systems (GNSSs). In operation, data is gathered from at
least four out of the 24 Defense Department satellites
orbiting 12,000 miles above the Earth. Unfortunately,
accuracy can be compromised by atmospheric
and is also
limited by the
use of a single
As a result,
accuracy within only about 1 to 5 m ( 3. 2 to 16. 4 ft).
This beats the now-decommissioned LORAN system,
but is still insufficient for such tasks as lane-level vehicle
navigation and mobile augmented reality.
The good news is that the recently expanded
Optical assembly process.
Broadcom’s BCM47755: More
accuracy, less power drain.