Quantum dots are crystal particles, with a diameter of tens to
thousands of atoms, that can absorb and emit different wavelengths of
light or move electric charges around. Now Prashant Jain, a chemistry
professor at the University of Illinois, has figured out a way to create
tunable quantum dots that can be adjusted on the fly. His innovation
could be key to designing optical computers and ultra-efficient solar
panels.
Jain makes quantum dots out of copper sulfide, varying
the ratio of copper atoms to sulfur atoms. At certain ratios, the amount
and distribution of electrical charges inside the dots becomes
sensitive to small changes in voltage—and it’s that charge distribution
that mostly determines the dots’ properties, such as which wavelengths
of light they’ll absorb and emit. “You can controllably push and pull
charges into these semiconductor nanocrystals and thus turn on and off
their ability to interact with light,” he explains.
That means
the dots could function as submicroscopic optical switches—potentially,
core components of an ultrafast optical computer that replaces
electricity with beams of light. Jain’s tunable-quantum-dot switch is
about one-sixth the size of today’s smallest transistors, and about a
hundredth the size of current optical switches. Jain is also making
quantum dots out of titanium oxide mixed with bismuth. These dots absorb
solar light and convert it to electrochemical energy, which is used to
generate hydrogen fuel from water.
Jain’s dots are still very
much in the research stage, and he predicts it will take an enormous
amount of additional research to achieve practical optical computers or
the super-efficient hydrogen production needed for energy applications.
“There’s a lot more fundamental work to be done,” he says.
Combining tools used to manufacture printed circuit boards with the
spirit of origami, Pratheev Sreetharan has found a way to build tiny
machines and complex objects that were previously impossible to
fabricate without assembling them manually. Some of the results: a
robotic bee created in a day, a tiny, precise icosahedron, and a small
chain of interlocking carbon-fiber links. The small, intricate items
demonstrate a fundamentally new fabrication approach that Sreetharan
believes can be broadly applicable in making a range of new medical
devices, robots, and components of analytical instruments.
If
Sreetharan is successful, he could open up the manufacturing
no-man’s-land between the micrometer-scale features of silicon chips
and the centimeter-plus scale of everyday items. It’s a size range
that’s of critical importance in biology and medicine. But today there’s
simply no practical way to mass-produce three-dimensional objects and
complex machines on this in-between scale.
Sreetharan’s prize
creation is the robot bee, fabricated through a series of steps inspired
by pop-up books. As a graduate student in the lab of Harvard
microrobotics pioneer Robert Wood (a member of the 2008 TR35),
Sreetharan was familiar with the task of laboriously gluing the
miniature robots together under a microscope, and his fabrication
approach was born of his determination to find a better way.
He
began by adapting standard lamination and micromachining techniques from
circuit board manufacturing to carve the needed parts into a flat
substrate. But the real trick came in adding features that allowed the
parts to pop up and lock into place in one step, creating the bee.
Sreetharan,
who spent a recent summer in the Indian region of Tamil Nadu teaching
Sri Lankan refugees about renewable energy and designing a solar-powered
computer charger, recently got his PhD from Harvard and founded a
startup called Vibrant Research in Cambridge, Massachusetts, to adapt
his fabrication methods to advanced manufacturing.
He is still deciding which specific products the company will focus
on, but he says he is able to routinely make objects that have never
before existed. And he hopes the novel production methods will create
new opportunities in manufacturing. That would be a pretty good way to
build on the buzz from his robot bee.
(Reported by David Rotman for TR35)
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Haptic Shoe For The Blind
Le Chal is an unobtrusive navigation aid for the visually impaired.
Imagine walking down to the nearest
grocery shop or a
bus stop with your eyes blindfolded and you’ll probably get an idea how tricky outdoor navigation for the visually impaired can be.
Arduino Lilypad is the main circuit board, which is kept at the
back mid-sole region of the shoe. The mini-vibrational actuators are
placed on all sides for the directional haptic feedback so that an
approaching turn triggers the vibration. See the slideshow for a full-coverage of how shoe-Le Chal works. (Credit: Sujith Sujan)
Sensitive towards the needs of the
visually impaired people, Anirudh Sharma, 24, a young researcher at Hewlett-Packard Labs in Bangalore, worked over several nights to
design a shoe
for the blind. Unlike other existing aids that are available in the
market for people with limited or no vision, this haptic shoe is simple
and unobtrusive in design, uses low-cost readily available components,
and provides tactile feedback to assist the visually impaired in their
day-to-day outdoor navigation tasks.
To Sharma the first idea of a haptic shoe struck at the Design and
Innovation workshop in Pune, Maharashtra, during 24-28 January, 2011.
The workshop was organized by Massachusetts Institute of Technology
(MIT) Media Lab and the College of Engineering, Pune to engage and
inspire students across all disciplines in Indian universities in
inventing the future. During the workshop Sharma, along with two other
technologists, created the first prototype of the haptic shoe and
showcased it to the delegates. The shoe was instantly named “
Le Chal” which is a Hindi translation of “Take Me There”.
At present people with limited or no vision depend either on
walking canes,
which help them detect obstructions, or seek help from friends and
other people for assistance, or using voice-based navigation aids. The
existing form of voice-based navigation aids can be very distracting for
the blind as they mostly depend on their sense of hearing. Such devices
are prohibitively expensive to buy too.
This motivated Sharma to create a shoe that could navigate the route
for the visually impaired and lead them to their desired destination
without hampering their hearing power or making them wear bulky stuff
and look awkward on the street.
The unobtrusive design of
Le Chal is its most significant
feature. The system comprises of a mechanism that condenses complex
geographical navigational information and lets the user feel the
directional and proximity information through vibrations. The vibrators
and proximity sensor put in one shoe of the pair enables the user to
walk without any physical aid.
All that the user requires is a
Le Chal shoe and a mobile phone with
global positioning
system (GPS). Once the user sets a destination on the phone before
starting the journey, the Bluetooth communication between the shoe and
phone does the rest. The phone fetches turn-by-turn Google maps data in
the background and keeps updating the user with haptic feedback about
the direction the user needs to turn to.
As soon as the user starts his or her journey, the GPS transmitter
within the cellphone gets real-time location using Google Maps. The
built-in compass in the GPS module calculates the direction user is
walking in. When the
turning point is
approached a mild vibrational feedback activated in the shoe informs the
user the direction he or she needs to turn to. The strength of the
vibration depends upon the overall proximity from the destination, that
is, vibration is weak in the beginning and is incrementally stronger at
the end of the navigation task. The built-in proximity sensor of the
shoe can detect up to 10 feet, informing the user of the surroundings
and allowing him or her to make decisions and plan the next move.
Sharma is planning to release the code of
Le Chal Android
application and schematics to public through Arduino community channel.
He is also planning to create a Do-It-Yourself (DIY) guide through an
editable Wikipedia where users can participate and help him create
better version of the technology. He is also exploring the idea of how
the commutation data of
multiple users could decrease the overall time.
( Reported by Vantika Dixit for TR35)
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Vivek Nair, 23 (Damascus Fortune, Mumbai)
Carbon nanotubes from carbon emissions
There are many technologies for carbon capture but Vivek Nair has
found an innovative way to convert carbon emissions into industry grade
carbon nanotubes. His company Damascus Fortune has forged partnerships
with several rice mills and carbon emitting
plants in India to produce carbon nanotubes. Even though there are
numerous applications of carbon nanotubes, most of the products are
still not in the market due to the high cost of the carbon nanotubes.
The challenge is in manufacturing these on a mass scale.
His invention uses a pressing problem (industrial and auto emissions) as a "raw material", applies transformative chemistry
using a regenerable catalyst, and produces innovative carbon nanotubes.
The process followed is a catalytic substrate exposed to the flow of
flue gas or flame coming out of the furnace to tap and produce carbon
nanotubes by a carbon vapor deposition process.
The main advantage of the invention is large-scale high yield
production of carbon filaments from pollution causing carbon emissions
from industrial and automobile exhausts. Nair has completed the basic research
and optimized the catalyst and substrate for a set of other industries
and automobiles too. And he has set his sight on automation instruments
that can continuously perform the carbon capture when the industrial
furnace or the automobile is in operation.
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VSK Murthy Balijepalli, 26 (Indian Institute of Technology, Bombay)
Forecasting the price and load of electricity
In May 2010, Government of India formed the IndianSmart Grid Task
Force to execute a $132 million (Rs.600 crore) pilot smart grid project
to demonstrate power saving measures and improve energy efficiency in
distribution networks across the country. VSK Murthy Balijepalli has
recently developed a novel method to forecast electricity price, grid
frequency and load which can assist in making power grids smarter. He
hopes his technology will find a place in the government proposed smart
grid pilot.
One of the key goals of a smart grid is to empower the consumers to
actively participate in the power demand-supply flow. Forecasting
electricity parameters such as price, grid frequency, and load can
facilitate consumers' participation in balancing the power demand-supply
ratio. Balijepalli's forecasting technology, called km-stochastic error
correction technique (km-SEC), uses robust regression algorithms and
artificial neural network to give accurate forecast of elecriticy price,
effective load, and grid frequency.
The algorithms use Indian Energy Exchange market clearing price
values, forecast values by industry standard software, and histroy of
errors as inputs to predict forecasts. "The maximum reduction of the
error for a day-ahead forecast of a single day is 3.35 percent when
km-SEC is used," says Balijepalli. He says, "The price forecasting will
help users to schedule electricity usage. Using the price forecasting
technology in a residential metering device can reduce the electricity
bill between 18.5 to 25.64 percent on day-ahead basis."
The km-SEC technology can also be used for effective load forecasting
which has multiple applications for the energy utilities, retailers,
and the captive power plants. Balijepalli's technology can be applied
with any forecasting model to improve the accuracy of predictions.
Accurate, near real-time price and load predictions will eventually lead
to shifting of transmission peaks, better outage management and
distribution system. Balijepalli has patented the km-SEC technology in
India. He is now planning to use the technology in European and U.S.
markets to assess its potential benefits.
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