Trees Used as Street Lights

11/24/2010 04:29:00 PM gadgets No Comments

Trees Used as Street Lights:


Taiwanese researchers have come up with the elegant idea of replacing streetlights with trees, by implanting their leaves with gold nanoparticles. This causes the leaves to give off a red glow, lighting the road for passersby without the need for electric power. This ingenious triple threat of an idea could simultaneously reduce carbon emissions, cut electricity costs and reduce light pollution, without sacrificing the safety that streetlights bring.

As many good things do, this discovery came about by accident when the researchers were trying to create lighting as efficient as LEDs without using the toxic, expensive phosphor powder that LEDs rely on. The gold nanoparticles, shaped like sea urchins, put into the leaves of Bacopa caroliniana plants cause chlorophyll to produce the reddish luminescence.

In an added bonus, the luminescence will cause the leaves’ chloroplasts to photosynthesize, which will result in more carbon being captured from the air while the streets are lit. The next steps are to improve the efficiency of the bioluminescence and apply the technology to other biomolecules.

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Largest Rocket Lifts Largest (SPY)Satellite Ever Into Space

11/24/2010 02:41:00 PM Space 1 Comment

Largest Rocket Lifts Largest Satellite Ever Into Space, Where It Will Spy on US Enemies

A behemoth spy satellite blasted into space Sunday night aboard the country’s biggest heavy-lift rocket, the second satellite launched by by the National Reconnaissance Office in the past three months. Stats on the megasat are classified, but the NRO boasted this fall that it would be the biggest satellite in the world.

Government officials won’t confirm what the satellite is for, but NROL-32’s huge antenna would make it possible to eavesdrop on enemy communications, as the BBC says. Satellite watchers believe it hosts sensitive radio receivers and an antenna spanning 328 feet across, nearly five times the size of the largest commercial antenna ever launched.

“This mission helps to ensure that vital NRO resources will continue to bolster our national defense,” said Air Force Brig. Gen. Ed Wilson, commander 45th Space Wing, after the launch. It had been delayed two days because of a temperature sensor glitch.United Launch Alliance, a partnership between Boeing and Lockheed Martin, launched the satellite aboard a Delta IV Heavy rocket. It was only the fourth launch for the Heavy since its 2004 debut, which launched a small demonstration satellite. It involves three boosters that provide 2 million pounds of thrust to send 13-ton payloads to geostationary orbit. The other two satellites were also secret spy payloads.



Last week, Boeing announced the successful launch of SkyTerra 1, which has a 72-foot-wide antenna reflector, the largest on a commercial satellite. The previous record was TerraStar-1’s 60-foot antenna.

Specs on the country's military and spy satellites are classified, but NRO director Bruce Carlson, a retired Air Force general, said at a conference in September that NROL-32 would be the biggest satellite in the world.

He added that the current plan for NRO satellite missions “is the most aggressive launch campaign that the National Reconnaissance Office has had in 20 years, almost a quarter of a century,” according to Space.com.

Satellite watchers told SpaceFlightNow and NASAspaceflight blogs they believe the payload is an electronic signals intelligence satellite; there are four already in orbit. ELINT satellites known as Mentor or Advanced Orion have been in service since 1995.

Delta IV Launch

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Top 10 Scientific Discoveries

11/14/2010 11:27:00 PM Science No Comments

1. Our Oldest Ancestor, "Ardi"

With her long, elegant fingers, 4-ft. frame and a head no larger than a bonobo's, it's hard not to feel a certain fondness for little Ardi, the oldest skeleton of a prehuman hominid ever found. Painstakingly pieced together from more than 100 crushed fossil fragments unearthed in Ethiopia, this female specimen of Ardipithecus ramidus (Ardi, for short) lived 4.4 million years ago and had remained anonymous until 1992, when her fragments were first discovered. After 17 years of research, a team of scientists led by Tim D. White from the University of California, Berkeley, published a comprehensive analysis of Ardi in October, in a series of articles in the journal Science. Among the team's revelations: Ardi was surprisingly unchimplike despite being the earliest known descendant of the last common ancestor shared by humans and chimps. Also, she was capable of walking on two feet despite living in an area of woodland and forest — a finding that downplays the importance of open grasslands to the evolution of human bipedalism.

2. The Human Epigenome, Decoded

The decoding of the human genome nearly a decade ago fueled expectations that an understanding of all human hereditary influences was within sight. But the connections between genes and, say, disease turned out to be far more complicated than imagined. What has since emerged is a new frontier in the study of genetic signaling known as epigenetics, which holds that the behavior of genes can be modified by environmental influences and that those changes can be passed down through generations. So people who smoke cigarettes in their youth, for example, sustain certain epigenetic changes, which may then increase the risk that their children's children will reach puberty early. In October, a team led by Joseph Ecker at the Salk Institute in La Jolla, Calif., studied human skin and stem cells to produce the first detailed map of the human epigenome. By comparing this with the epigenomes of diseased cells, scientists will be able to work out how glitches in the epigenome may lead to cancers and other diseases. The study, which was published in the journal Nature, is a giant leap in geneticists' quest to better understand the strange witches' brew of nature and nurture that makes us who we are.

3. Gene Therapy Cures Color Blindness

Modern science already offers ways to enhance your mood, sex drive, athletic performance, concentration levels and overall health, but a discovery in September suggests that truly revolutionary human enhancement may soon move from science fiction to reality. A study in Nature reported that a team of ophthalmologists had injected genes that produce color-detecting proteins into the eyes of two color-blind monkeys, allowing the animals to see red and green for the first time. The results were shocking to most — "We said it was possible, but every single person I talked to said, 'Absolutely not,' " said study co-author Jay Neitz of the University of Washington — and raised the possibility that a range of vision defects could someday be cured. That's a transformative prospect in itself, but the discovery further suggests that it may be possible to enhance senses in "healthy" people too, truly revolutionizing the way we see the world.

4. A Robot Performs Science

By any standard, it was an elementary discovery — the identification of the role of about a dozen genes in a yeast cell. But what made this finding a major breakthrough was the unlikely form of the scientist: a robot. In April, "Adam," a machine designed at Aberystwyth University in Wales, became the first robotic system to make a novel scientific discovery with virtually no human intellectual input. Robots have long been used in experiments — their vast computational power assisted in the sequencing of the human genome, for example — but Adam was the first to complete the cycle from hypothesis to experiment to reformulated hypothesis without human intervention. Interviewed after Adam's experiment appeared in Science, inventor Ross King argued that artificial intelligence had almost limitless scientific potential — and that a computer would one day make a discovery akin to Einstein's special theory of relativity. "There isn't any intrinsic reason why that wouldn't happen," he said. "A computer can make beautiful chess moves, but it's not doing anything special. In my view, that's what's going to happen in science."

5. Breeding Tuna on Land

In Australia, a tankful of southern bluefin tuna — regal, predatory fish prized for their buttery sashimi meat — began to spawn, and they didn't stop for more than a month. "People said, 'It can't be done, it can't be done,' " said Hagen Stehr, founder of Clean Seas, the Australian company that operates the breeding facility. "Now we've done it." Scientists believe that the breeding population of the highly migratory southern bluefin has probably plummeted more than 90% since the 1950s. Others have gotten Pacific bluefin to spawn and grow in ocean cages, but by coaxing the notoriously fussy southern bluefin to breed in landlocked tanks, Clean Seas may finally have given the future of bluefin aquaculture legs.

6. Water on the Moon

There is water on the moon, scientists stated unequivocally in November. Gallons of it. On Oct. 9, NASA used a rocket to punch a hole about 100 ft. across the moon's surface, then measured about 25 gal. of water vapor and ice in the resulting debris. Some scientists speculated that there may be enough water in the craters of the moon's poles to sustain future colonies of astronauts. Others said the ice could hold a historical record of the solar system. NASA said the first priority was to figure out where the water came from and measure how much of it there is. Meanwhile, the discovery had a more immediate and widespread impact among the rest of us: the rekindling of an old thrill. In 2009, the moon, our recently neglected neighbor, regained her mystery.

7. The Fundamental Lemma, Solved

In 1979 the Canadian-American mathematician Robert Langlands developed an ambitious and revolutionary theory that connected two branches of mathematics called number theory and group theory. In a dazzling set of conjectures and insights, the theory captured deep symmetries associated with equations that involve whole numbers, laying out what is now known as the Langlands program. Langlands knew that the task of proving the assumptions that underlie his theory would be the work of generations. But he was convinced that one stepping stone that needed confirmation — dubbed the "fundamental lemma" — would be reasonably straightforward. He, his collaborators and his students were able to prove special cases of this fundamental theorem. But proving the general case proved more difficult than Langlands anticipated — so difficult, in fact, that it took 30 years to finally achieve. Over the past few years, Ngo Bao Chau, a Vietnamese mathematician working at Université Paris-Sud and the Institute for Advanced Study (IAS) in Princeton, formulated an ingenious proof of the fundamental lemma. When it was checked this year and confirmed to be correct, mathematicians around the globe breathed a sigh of relief. Mathematicians' work in this area in the last three decades was predicated on the principle that the fundamental lemma was indeed accurate and would one day be proved. "It's as if people were working on the far side of the river waiting for someone to throw this bridge across," says Peter Sarnak, a number theorist at IAS. "And now all of sudden everyone's work on the other side of the river has been proven."

8. Teleportation!

Inching our reality ever closer to Star Trek's, scientists at the University of Maryland's Joint Quantum Institute successfully teleported data from one atom to another in a container a meter away. A landmark in the brain-bending field known as quantum information processing, the experiment doesn't quite have the cool factor of body transportation; one atom merely transforms the other so it acts just like the first. Still, atom-to-atom teleportation has major implications for creating supersecure, ultra-fast computers.

9. The Large Hadron Collider, Revived

It is largest science experiment ever conducted. The Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, took a quarter of a century to plan and about $10 billion to build. Housed in a 17-mile underground ring, the LHC has been designed to accelerate particles at temperatures colder than that of deep space to a velocity approaching the speed of light. Beset by a series of hiccups and delays, the CERN scientists on Nov. 29 finally recorded a benchmark achievement, powering up a proton beam to an energy of 1.05 trillion electron volts (TeV), overtaking the Tevatron accelerator at Fermilab in Illinois as the world's most powerful accelerator. Eventually the machine will power up to as much as 7 TeV, causing collisions of such high energy that they will re-create the conditions in the seconds after the Big Bang. Amid the by-products of these collisions, physicists will be searching for signs of a hypothetical subatomic particle called the Higgs boson, which according to current theory is responsible for imparting mass to all things in the universe. Other scientists are hoping for even deeper clues, like confirmation of an ambitious theory called supersymmetry. Let the physics begin.

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'Debugging Day' Infamous Software Bugs

9/15/2010 03:10:00 PM Software Testing No Comments

September 9 was Debugging Day. It's been associated with removing bugs for more than 50 years now but is rarely formally celebrated. So let's start the tradition this year.
some bugs have wreaked disaster, embarrassment and destruction on the world. Some have literally killed people.

It all began with a log entry from 1947 by Harvard University's Mark II technical team. The now-classic entry features a moth taped to the page, time-stamped 15:45, with the caption "Relay #70 Panel F (moth) in relay" and the proud boast, "First actual case of bug being found." (Click on the image for a close-up view of the historic logbook.)

End-of-the-World Bugs

Remember how the world descended into nuclear oblivion on September 23, 1983? No? Well, thank your lucky stars -- this is a tale of bugs so major they could have brought the entire world to a standstill.

Illustration: Lou BeachIt was all averted by the common sense of one individual, who ignored the Soviet early-warning system's faulty reports of incoming missiles and didn't launch a counterattack on the United States.

The warning system set off klaxons at half past midnight on that September morning. Apparently, the U.S. had launched five nuclear missiles toward what the U.S. president had taken to calling "the Evil Empire."

At the time, Lt. Col. Stanislaus Petrov reasoned his way to a decision not to respond: The USSR was in a shouting match with the U.S. about a Soviet attack on Korean Air Lines Flight 007 three weeks earlier, but it was only a rhetorical battle at that stage. Besides, if the U.S. wanted to attack the Soviet Union, would it really launch only five missiles?

Petrov ordered his men to stand down, and 15 minutes later, radar outposts confirmed that there were no incoming missiles. The decision took less than five minutes, it was confirmed within half an hour, and the world remained at peace.

When the early-warning system was later analyzed, it was found to have more bugs than a suburban compost heap -- which meant that although Stanislaus Petrov had saved the world, he'd made a serious error of judgment: He had shown up the incompetence of Soviet programmers.

This was not good for morale, or for the lieutenant colonel. He was cold-shouldered into an early retirement and was largely unsung until May 21, 2004, when a San Francisco-based organization called the Association of World Citizens bestowed its highest honor -- world citizenship -- and a financial reward on him.

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Researchers Announce First Implantable Artificial Kidney Prototype

9/06/2010 02:17:00 AM Research, Science No Comments

First Implantable Artificial Kidney Prototype:

Artificial Kidney Thousands of nano-filters remove toxins from the blood, while a BioCartridge of renal tubule cells mimics the metabolic and water-balance roles of the human kidney. UCSF via ScienceDaily

An artificial kidney powered by the circulatory system could be the first implantable device to replace kidney donation and dialysis, scientists say.

Led by a University of California-San Francisco scientist, a consortium of about 10 different research teams unveiled a new artificial kidney prototype this week, saying a room-sized version has already shown promise for the sickest patients. Fabrication processes used to make silicon chips could conceivably be used to make coffee-cup-sized devices, which could take thousands of people off dialysis machines or kidney-donor waiting lists.

The multi-institutional team, led by UCSF professor Shuvo Roy, formerly of the Cleveland Clinic, is the first to demonstrate technology that could be feasibly downsized into a transplant device.

It’s a two-stage system involving thousands of nanoscale filters placed in a “BioCartridge,” which would remove toxins from the blood. A "HemoCartridge" bioreactor made of engineered renal tubule cells would mimic the metabolic and water-balancing roles of a real kidney. The system uses a patient’s blood pressure to perform filtration without the use of pumps, according to aUCSF news release.



Currently, transplants and dialysis are the only ways to treat kidney failure. An implantable device would obviously be preferable, but so far, scientists have not been able to come up with a system that mimics everything the kidney can do.

The new system relies on the latest advances in nanotechnology and tissue generation, Roy said. He hopes to use silicon-fabrication technology to make the device small enough for transplant.

“This could dramatically reduce the burden of renal failure for millions of people worldwide, while also reducing one of the largest costs in U.S. healthcare,” he said.

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Complicated Mechanism Explained via Simple Animations

8/28/2010 09:05:00 PM Science No Comments

Complicated Mechanism Explained via Simple Animations:

Radial Engines
Radial engines are used in aircrafts having propeller connected to the shaft delivering power in order to produce thrust its basic mechanism is as follows

Steam engine Principle

Steam engine once used in locomotives was based on the reciprocating principle as shown below

Sewing Machine

Maltese Cross Mechanism

this type of mechanism is used in clocks to power the second hand movement.

Manual Transmission Mechanism

The mechanism also called as “stick shift” is used in cars to change gears mannually

Constant Velocity Joint

This mechanism is used in the front wheel drive cars

Constant-velocity joints (aka homokinetic or CV joints) allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play. They are mainly used in front wheel drive and all wheel drive cars. Rear wheel drive cars with independent rear suspension typically use CV joints at the ends of the rear axle halfshafts, and increasingly use them on the propshafts.

Torpedo-Boat destroyer System

This system is used to destroy fleet in naval military operations.

Rotary Engine

Also called as Wankel engine is a type of internal combustion engine has a unique design that converts pressure into rotating motion instead of reciprocating pistons

ZIP

Proving the Pythagorean Theorem Through Rearrangement

How an Alpha Stirling Engine Works

A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work. Or more specifically, a closed-cycle regenerative heat engine with a permanently gaseous working fluid, where closed-cycle is defined as a thermodynamic system in which the working fluid is permanently contained within the system, and regenerative describes the use of a specific type of internal heat exchanger and thermal store, known as the regenerator. It is the inclusion of a regenerator that differentiates the Stirling engine from other closed cycle hot air engines.

How a Hypotrochoid is Made

A hypotrochoid is a roulette traced by a point attached to a circle of radius r rolling around the inside of a fixed circle of radius R, where the point is a distance d from the center of the interior circle.

Illustrating Pi: Unrolling a Circle’s Circumference

How the Sun and Planet Gear Works

The sun and planet gear (also called the planet and sun gear) was a method of converting reciprocal motion to rotary motion and was utilised in a reciprocating steam engine. It was invented by the Scottish engineer William Murdoch, an employee of Boulton and Watt, but was patented by James Watt in October 1781. It was invented to bypass the patent on the crank, held by James Pickard. It played an important part in the development of devices for rotation in the Industrial Revolution.

How a Pill Press Works

Tablet press is a mechanical device that compresses powder into tablets of uniform size and weight. A press can be used to manufacture tablets of a wide variety of materials, including pharmaceuticals, illicit drugs such as MDMA, cleaning products, and cosmetics. To form a tablet, the granulated material must be metered into a cavity formed by two punches and a die, and then the punches must be pressed together with great force to fuse the material together.

Knight’s Tour: How a Knight Visits Every Square Once

A knight’s tour is a sequence of moves of a knight on a chessboard such that the knight visits every square exactly once. The exact number of open tours on an 8×8 chessboard is still unknown.

Creating a program to find a knight’s tour is a common problem given to computer science students. Variations of the knight’s tour problem involve chessboards of different sizes than the usual 8 × 8, as well as irregular (non-rectangular) board

How Walschaerts Valve Gear in Steam Locomotives Works

The Walschaerts valve gear is a type of valve gear invented by Belgian railway mechanical engineer Egide Walschaerts in 1844 used to regulate the flow of steam to the pistons in Steam Engines. The gear is sometimes named without the final “s”, since it was incorrectly patented under that name. It was extensively used in steam locomotives from the late 19th century until the end of the steam era.

What a Tesseract (4D Cube) Looks Like

In geometry, the tesseract, also called an 8-cell or regular octachoron or cubic prism, is the four-dimensional analog of the cube; the tesseract is to the cube as the cube is to the square. Just as the surface of the cube consists of 6 square faces, the hypersurface of the tesseract consists of 8 cubical cells.

How Circle Strafing Works

In video games, strafing is the technique of moving the player’s character from side to side, rather than forward and backward. Circle strafing is the technique of moving around a target in a circle while facing it. Circle strafing allows a player to fire continuously at an opponent while dodging counterattacks. By rapidly circling the opponent, the player evades the opponent’s sights.

How a Caliper Works

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Using Einstein's Relativity to Speed up Supercomputer Simulations 10,000%

8/25/2010 11:59:00 PM Science No Comments

Using Einstein's Relativity to Speed up Supercomputer Simulations 10,000%

Physicists realized it's not the algorithm or the hardware, but the reference frame that needed an update.

Sometimes when you need to break a computational log-jam, what's required isn't more power, but a conceptual breakthrough. And sometimes that breakthrough comes directly from the work of Albert Einstein.

In this case, the problem at hand is the simulation of lasers hitting plasmas - which is one of those bleeding-edge areas of physics that could lead to, according to a2008 summary of the field, "proton therapy for the treatment of cancers, materials characterization, radiation-driven chemistry, border security through the detection of explosives, narcotics and other dangerous substances, and of course high-energy particle physics."

Or in other words, desktop particle accelerators.

But before we can build accelerators as capable as CERN's Large Hadron Collider in the comfort of our underground lairs, we first have to use computers to model the behavior of these so-called "laser-plasma accelerators."

Even on the world's 17th fastest supercomputer, this turns out to be a Herculean task.

And here comes the breakthrough: Physicists realized that because the laser is accelerating electrons in its path to nearly the speed of light, Relativistic effects start to be a big deal - the same effects first discovered by Albert Einstein.

And if we remember anything from A Brief History of Time or even the original Planet of the Apes, it's that at speeds approaching the speed of light, where the observer is standing has a huge impact on what they perceive - this is, for example, the reason that an astronaut traveling close to the speed of light would age much slower than the people he or she left behind on earth.

Previously, all simulations of laser-plasma accelerators were run from the perspective of a physicist standing somewhere in the vicinity of the experiment - in other words, someone who sees a super short laser pulse traveling at a near-stationary plasma. Mathematically, this is very hard to simulate - the laser is brief.

But what if, instead, we take the perspective of the plasma itself? Now, relative to the laser, it's as if the plasma is traveling toward the beam of light at near-light speed. Because of relativistic effects, this stretches out the beam of the laser, making it longer and mathematically more tractable to simulate.

Voila - the resulting algorithm is hundreds of times faster than previous attempts to simulate a laser-plasma accelerator

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Exoskeleton system ready for soldier tests

7/22/2010 02:22:00 PM gadgets, robot No Comments

Exoskeleton system ready for soldier tests:

A robotic exoskeleton that makes it easier for soldiers to run and carry heavy weights is to go through final testing in the US.

The HULC (Human Universal Load Carrier) allows soldiers to carry weights of up to 200lbs (91kg) with little effort and is designed to reduce the strain of carrying heavy equipment.

It works by transferring the load to the ground through the exoskeleton's titanium legs and uses an onboard computer to sense and mimic the user's movements.

The battery powered device, which can fit different body sizes, also allow for jumps, squats, crawling and slow-speed running.

"It does not impede your range of motion whatsoever," says HULC project manager Jim Ni.

"Just imagine you're a soldier operating at 6,000ft in the Afghan mountains and being asked to take 120lbs up there in the thin air.

The HULC allows soldiers to carry weight of up to 91kg with little effort

"An exoskeleton allows you to carry that weight the same distance and have energy left to execute the mission when you get there."

Although the HULC weighs 53lbs (24kg), its makers say it also transfers its own weight to the ground, making it virtually unnoticeable.

Lockheed Martin, which makes the device, has reworked an earlier prototype and produced a new "ruggedized design" that will begin an eight week lab test at the end of 2010.

The testing will look at how quickly people learn to operate the system and measure the energy a soldier uses when using the HULC.

"The tests will help us assess the current state of the technology," said David Audet, from the US Army's Natick Soldier Research Center.

"Exoskeletons have the potential to reduce stress on the body from heavy loads."

After the lab tests, the HULC is likely to go through more field tests in 'real-life' military scenarios during 2011

(via bbc)

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A Tiny Power House for Home- Bloom Box

7/04/2010 03:19:00 PM 1 Comment

A Tiny Power House for Home- BloomBox

Fuel cells have been a tantilizing technolgy for decades - powering space vehicles, but always a little out of reach for domestic or commercial use. I worked with Greenopolis Partner Plug Power for years - working to provide clean on site energy from hydrogen powered fuel cells. Now there’s the Bloom Box

That’s not a typo for a new carry-on-your shoulder stereo system. The Bloom Box is a refrigerator-sized box that can power your whole house, store or business.

Bloom Energy is a venture capital funded firm that builds the “Bloom Box”- an appliance sized unit that houses fuel cells running on natural gas, landfill gas, bio-gas or solar power. Fuel cells combine hydrogen with oxygen and emit only heat, electricity and distilled water.

Google has been powering a datacenter with 4 Bloom Boxes running on natural gas for the past year and a half. eBay has 5 of them in San Jose, which they claim have saved them $100,000 in energy costs over the past 9 months.


Watch CBS News Videos Online

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This EMP Cannon Gun (to halt cars immediate )

6/10/2010 10:59:00 AM gadgets No Comments

This EMP Cannon Gun (to halt cars immediate )


We've heard of electromagnetic pulses cutting steel in milliseconds, but apparently they can also be used to stop moving cars just as fast. The cannon demonstrated in the video here is still a prototype, but it definitely seems to work.

The idea is that an electromagnetic pulse would be used to disable a car's microprocessors, chips, and whatever other electronics are keeping it running. The final "cannon" system, built by Eureka Aerospace, will apparently a bit smaller and lighter than what we see in the video—it'll be suitcase-sized and about 50 pounds—and it will "stop cars in their tracks up to 656 feet (200 m) away."

I wish they tested that cannon on a moving car, but it does just what it should by disabling the car's electrical system. Only trouble is that even once the system is perfected and in use it can still be foiled easily: By using a pre-1970s car which doesn't "rely on microprocessors." Whoops.

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Bionic Hand for disabled

6/06/2010 09:57:00 PM gadgets No Comments

Bionic Hand for Disabled.

The long deserted issue, the human body, has come across the industrial designer’s path, resulting the innovative and functional METIS concept that has been designed to redefine the future of human. Being connected with the human nervous system, this prosthesis concept can provide an amputee his access to the existing virtual dimensions around us by giving back his limb. Moreover, only if you can overlook the reality of a flesh and blood hand, this prosthesis features more advanced technologies than a real hand such as 360 degrees rotating ability of the arm, 3G, Wi-Fi, LCD display and rechargeable lithium-ion batteries to power the electric elements. With all these functional features, who knows, maybe future people will consider altering their real hand with METIS.

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Generating Power from a Heart

6/06/2010 09:47:00 PM gadgets, Science 1 Comment

Generating Power from a Heart

Nanowire generators could one day lead to medical devices powered by the patient's own heart.

A tiny, nearly invisible nanowire can convert the energy of pulsing, flexing muscles inside a rat's body into electric current, researchers at Georgia Institute of Technology have shown. Their nano generator could someday lead to medical implants and sensors powered by heartbeats or breathing.

Zinc oxide nanowires show the piezoelectric effect, producing electricity when they are under mechanical stress. Georgia Tech professor of materials science and engineering Zhong Lin Wang and his group first demonstrated these nanowire generators in 2005. Since then they have made devices that can harness the energy of a running hamster and tapping fingers, and have also combined their piezoelectric nanowires with solar cells.

In their latest work, published in the journal Advanced Materials, Wang's team shows that the nanogenerator works inside a live animal. The researchers deposited a zinc oxide nanowire on a flexible polymer substrate and encapsulated the device in a polymer casing to shield it from body fluids. It was then attached to a rat's diaphragm. The rodent's breathing stretched the nanowire, and the device generated four picoamperes of current at two millivolts. When attached to a rat's heart, the device gave 30 picoamperes at three millivolts.

Zinc oxide nanogenerators would be an ideal power source for nano-scale sensors that monitor blood pressure or glucose levels and detect cancer biomarkers. These can run on low power levels of about one microwatt, but they need a long-lasting nano-sized power source instead of a battery to be truly nano scale. "Our ultimate goal is to make self-powered nano devices for medical applications," says Wang.



The femtowatt scale of power generated by the devices is far too low to be practical right now (power = current x voltage). But that should change soon, Zhang says. While the researchers have only tested a single nanowire device inside a rat, they have also built a device that integrates hundreds of nanowires in an array. This device, which the researchers recently reported in the journal Nature Nanotechnology, gives an output current of about 100 nanoamperes at 1.2 volts, producing 0.12 microwatts of power. Wang says the next step is to connect this higher-output nanogenerator to a nano sensor inside an animal.

Better piezoelectric materials than zinc oxide nanowires exist and are also being considered for biomedical applications. The most efficient piezoelectric material known is PZT, a compound of lead, zirconium, and titanium. It is 10 times more efficient than zinc oxide at converting mechanical stress into electric current, says Michael McAlpine, a mechanical engineering professor at Princeton University. By sandwiching PZT between silicone pieces, he has made a material that can harvest 80 percent of the energy applied when flexed. Like Wang, he is focusing on using the material to power medical implants.

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