David Kirkpatrick

September 1, 2010

Nanotech making water more safe

This development can make a real quality of life difference in developing countries without running water and disaster areas, and it can make “roughing it” just a little bit less rough.

The release:

High-speed filter uses electrified nanostructures to purify water at low cost

IMAGE: This scanning electron microscope image shows the silver nanowires in which the cotton is dipped during the process of constructing a filter. The large fibers are cotton.

Click here for more information.

By dipping plain cotton cloth in a high-tech broth full of silver nanowires and carbon nanotubes, Stanford researchers have developed a new high-speed, low-cost filter that could easily be implemented to purify water in the developing world.

Instead of physically trapping bacteria as most existing filters do, the new filter lets them flow on through with the water. But by the time the pathogens have passed through, they have also passed on, because the device kills them with an electrical field that runs through the highly conductive “nano-coated” cotton.

In lab tests, over 98 percent of Escherichia coli bacteria that were exposed to 20 volts of electricity in the filter for several seconds were killed. Multiple layers of fabric were used to make the filter 2.5 inches thick.

“This really provides a new water treatment method to kill pathogens,” said Yi Cui, an associate professor of materials science and engineering. “It can easily be used in remote areas where people don’t have access to chemical treatments such as chlorine.”

Cholera, typhoid and hepatitis are among the waterborne diseases that are a continuing problem in the developing world. Cui said the new filter could be used in water purification systems from cities to small villages.

Faster filtering by letting bacteria through

Filters that physically trap bacteria must have pore spaces small enough to keep the pathogens from slipping through, but that restricts the filters’ flow rate.

IMAGE: This is professor of materials science and engineering Yi Cui.

Click here for more information.

Since the new filter doesn’t trap bacteria, it can have much larger pores, allowing water to speed through at a more rapid rate.

“Our filter is about 80,000 times faster than filters that trap bacteria,” Cui said. He is the senior author of a paper describing the research that will be published in an upcoming issue of Nano Letters. The paper is available online now.

The larger pore spaces in Cui’s filter also keep it from getting clogged, which is a problem with filters that physically pull bacteria out of the water.

Cui’s research group teamed with that of Sarah Heilshorn, an assistant professor of materials science and engineering, whose group brought its bioengineering expertise to bear on designing the filters.

Silver has long been known to have chemical properties that kill bacteria. “In the days before pasteurization and refrigeration, people would sometimes drop silver dollars into milk bottles to combat bacteria, or even swallow it,” Heilshorn said.

Cui’s group knew from previous projects that carbon nanotubes were good electrical conductors, so the researchers reasoned the two materials in concert would be effective against bacteria. “This approach really takes silver out of the folk remedy realm and into a high-tech setting, where it is much more effective,” Heilshorn said.

Using the commonplace keeps costs down

But the scientists also wanted to design the filters to be as inexpensive as possible. The amount of silver used for the nanowires was so small the cost was negligible, Cui said. Still, they needed a foundation material that was “cheap, widely available and chemically and mechanically robust.” So they went with ordinary woven cotton fabric.

“We got it at Wal-mart,” Cui said.

To turn their discount store cotton into a filter, they dipped it into a solution of carbon nanotubes, let it dry, then dipped it into the silver nanowire solution. They also tried mixing both nanomaterials together and doing a single dunk, which also worked. They let the cotton soak for at least a few minutes, sometimes up to 20, but that was all it took.

The big advantage of the nanomaterials is that their small size makes it easier for them to stick to the cotton, Cui said. The nanowires range from 40 to 100 billionths of a meter in diameter and up to 10 millionths of a meter in length. The nanotubes were only a few millionths of a meter long and as narrow as a single billionth of a meter. Because the nanomaterials stick so well, the nanotubes create a smooth, continuous surface on the cotton fibers. The longer nanowires generally have one end attached with the nanotubes and the other end branching off, poking into the void space between cotton fibers.

“With a continuous structure along the length, you can move the electrons very efficiently and really make the filter very conducting,” he said. “That means the filter requires less voltage.”

Minimal electricity required

The electrical current that helps do the killing is only a few milliamperes strong – barely enough to cause a tingling sensation in a person and easily supplied by a small solar panel or a couple 12-volt car batteries. The electrical current can also be generated from a stationary bicycle or by a hand-cranked device.

The low electricity requirement of the new filter is another advantage over those that physically filter bacteria, which use electric pumps to force water through their tiny pores. Those pumps take a lot of electricity to operate, Cui said.

In some of the lab tests of the nano-filter, the electricity needed to run current through the filter was only a fifth of what a filtration pump would have needed to filter a comparable amount of water.

The pores in the nano-filter are large enough that no pumping is needed – the force of gravity is enough to send the water speeding through.

Although the new filter is designed to let bacteria pass through, an added advantage of using the silver nanowire is that if any bacteria were to linger, the silver would likely kill it. This avoids biofouling, in which bacteria form a film on a filter. Biofouling is a common problem in filters that use small pores to filter out bacteria.

Cui said the electricity passing through the conducting filter may also be altering the pH of the water near the filter surface, which could add to its lethality toward the bacteria.

Cui said the next steps in the research are to try the filter on different types of bacteria and to run tests using several successive filters.

“With one filter, we can kill 98 percent of the bacteria,” Cui said. “For drinking water, you don’t want any live bacteria in the water, so we will have to use multiple filter stages.”

Cui’s research group has gained attention recently for using nanomaterials to build batteries from paper and cloth.


David Schoen and Alia Schoen were both graduate students in Materials Science and Engineering when the water-filter research was conducted and are co–lead authors of the paper in Nano Letters. David Schoen is now a postdoctoral researcher at Stanford.

Liangbing Hu, a postdoctoral researcher in Materials Science and Engineering, and Han Sun Kim, a graduate student in Materials Science and Engineering at the time the research was conducted, also contributed to the research and are co-authors of the paper.

August 13, 2010

Stock options do improve corporate performance

Particularly stock options for the c-level.

August 3, 2010

A completely new path to solar efficiency?

Maybe so. And if so this sounds very promising. I’ll go ahead and repeat my solar energy mantra — two things both have to happen before solar is truly economically viable: costs must come down quite a bit, and the efficiency has to at least be within spitting distance of petroleum and other traditional natural resources. This sounds like very good news on the efficiency front. Might even offer some cost benefits as well.

From the link:

Stanford engineers have figured out how to simultaneously use the light and heat of the sun to generate electricity in a way that could make solar power production more than twice as efficient as existing methods and potentially cheap enough to compete with oil.

Unlike photovoltaic technology currently used in  – which becomes less efficient as the temperature rises – the new process excels at higher temperatures.

Called ‘photon enhanced thermionic emission,’ or PETE, the process promises to surpass the efficiency of existing photovoltaic and thermal conversion technologies.

“This is really a conceptual breakthrough, a new  process, not just a new material or a slightly different tweak,” said Nick Melosh, an assistant professor of materials science and engineering, who led the research group. “It is actually something fundamentally different about how you can harvest energy.”

And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable.

A small PETE device made with cesium-coated gallium nitride glows while being tested inside an ultra-high vacuum chamber. The tests proved that the process simultaneously converted light and heat energy into electrical current. Credit: Photo courtesy of Nick Melosh, Stanford University

July 27, 2010

Artificial photosynthesis

I’ll keep my contribution here short and sweet — very interesting.

From the link:

The U.S. Department of Energy has awarded $122 million to establish a research center in California to develop ways of generating fuel made from sunlight. The project will be led by researchers at Caltech and the Lawrence Berkeley National Laboratory, and will include researchers at various other California institutions, including Stanford University, the University of California, Irvine, and the University of California, Berkeley.

Sun-soaked silicon: Researchers at the new Joint Center for Artificial Photosynthesis will work to optimize light-trapping silicon microwires, like these, to produce fuel from solar energy.

Credit: Nate Lewis, Caltech

July 22, 2010

Improving the application of nanocoatings

Nanocoatings do a lot of good, particularly with making solar cells more efficient. The trick is they haven’t been too easy to apply to big areas. Researchers at Stanford have helped change that issue.

From the link:

Nanoscale wires, pores, bumps, and other textures can dramatically improve the performance of solar cells, displays, and even self-cleaning coatings. Now researchers at Stanford University have developed a simpler, cheaper way to add these features to large surfaces.

Nanoscale structures offer particular advantages in devices that interact with light. For example, a thin-film solar cell carpeted with nano pillars is more efficient because the pillars absorb more light and convert more of it into electricity. Other nanoscale textures offer similar advantages in optical devices like display backlights.

The problem is scaling up to large areas, says Yi Cui, a Stanford professor of materials science and engineering who led the new work. “Many methods are really complex and don’t solve the problem,” says Cui. Lithography can be used to carve out nanoscale features with precise dimensions, but it’s expensive and difficult. Simpler techniques, such as spin-coating a surface with nanoparticles or using acids to etch it with tiny holes, don’t allow for much precision.

Nanosphere smear: Using a spinning rod to deposit an ink suspension of silica nanospheres is a simple way to create bumpy, nanotextured coatings like these three.

Credit: ACS/Nano Letters

July 15, 2010

Culture-growing adult stem cells

Filed under: Science — Tags: , , , , — David Kirkpatrick @ 10:25 pm

News on the stem cell research front.

From the link:

Researchers at the Stanford University School of Medicine have developed a technique they believe will help scientists overcome a major hurdle to the use of adult stem cells for treating muscular dystrophy and other muscle-wasting disorders that accompany aging or disease: They’ve found that growing muscle stem cells on a specially developed synthetic matrix that mimics the elasticity of real muscle allows them to maintain their self-renewing properties.

July 12, 2010

Tiny satellites …

… are changing astrobiology research for the better.

Just check these things out:

Small satellites such as the commonly used 10 cm x 10 cm x 10 cm CubeSat are easier and cheaper to put into low-Earth orbit. Credit: Weber State University

Also from the link:

The biggest advantage of nano- and pico-satellites is that they are a bargain. Most of the cost saving comes at the launch stage. Unlike conventional satellites, they don’t need a dedicated launch vehicle where they are the primary payload. “They’re so small they can hitch a ride on somebody else’s rocket,” Santos says. NASA’s nanosatellite missions cost two million a piece as opposed to the tens of millions needed for a conventional satellite.

Their affordability also comes from being built with off-the-shelf electronic circuit chips such as microprocessors and radio frequency transmitters and receivers. These are the same components that are inside smart phones, hand-held Global Positioning System units, and digital cameras.

In fact, the miniaturization of electronics has been the driving force behind small satellite technology, making it affordable, says Twiggs. “Electronics today are much more power-efficient than electronics of the past; that helps us,” he says. “Ten or fifteen years ago we couldn’t have found the components for the price that we could’ve afforded.”

May 28, 2010

Open source robotics

A great idea and ought to really help out robotics hobbyists.

From the link:

Robotics company Willow Garage has started a two-year project to work with institutions from around the world on new applications for its robot: the PR2. Each of 11 teams will work on their own projects, but will share their code with each other and the rest of the world. Everything created will be open-source, meaning others can use the code for their own endeavors. (The PR2 runs on a software platform called Robot Open Source, also developed by Willow Garage.)

April 20, 2010

Nanophotonic technology and solar cell efficiency

Fascinating research on the upper limit of light absorption by solar cells. Utilizing nanophotonic technology and thin-film solar cells, the efficiency is given an impressive boost. I keep hammering on the same point, but cost and efficiency in combination are the key to making solar a commercially viable option. Throw in some short-term government subsidies (I know, I know) and we are getting close to that sweet spot.

From the link:

But things have changed since the 1980s, not least because it is now possible to make layers of silicon much thinner than the wavelength of the light they are expected to absorb and to carve intricate patterns in these layers. How does this nanophotonic technology change the effect of light trapping?

Today, Zongfu Yu and buddies at Stanford University in California, tackle this question and say that nanophotonics dramatically changes the game.

That’s basically because light trapping works in a different way on these scales. Instead of total internal reflection, light becomes trapped on the surface of nanolayers, which act like waveguides. This increases the amount of time the photons spend in the material and so also improves the chances of absorption.

Because of the geometry of the layers, some wavelengths are trapped better than others and this gives rise to resonances at certain frequencies.

What Yu and co show is that by designing the layers in a way that traps light effectively, it is possible to beat the old limit by a substantial margin.

Also from the link:

Physicists have long known that thinner solar cells are better in a number of ways: they use less material and so are cheaper to make and the electrons they produce are easier to collect making them potentially more efficient. Now they know that light trapping is more effective in thinner layers too.

March 2, 2010

Your avatar affects your online behavior

Via KurzweilAI.net — This research is not surprising in the least. If your avatar looks like you it stands to reason you’d act something akin to how you normally would. If your avatar has a dramatically different look than you, or is a different gender, species or even an alien life form it also stands to reason you’d be more likely to role-play the actions you think that character would exhibit.

Can avatars change the way we think and act?
Physorg.com, Feb. 25, 2010

You are more likely to imitate the behavior of an avatar in real life if it looks like you, Jesse Fox, a researcher at the Stanford Virtual Human Interaction Lab, found in a study that used digital photographs of participants to create personalized avatar bodies.

Read Original Article>>

Here’s the YouTube clip found at the link:

February 20, 2010

Paper batteries and eTextiles

The 2010 AAAS (American Association for the Advancement of Science) annual meeting is going on as I type, so there is a lot of news coming out fast and furious from the conference. I’m going to try and restrain myself and only post what really strikes my fancy, or what sounds like a game-changing advancement in any particular field.

Like I regularly do, this news will presented in the form of the raw press release. Yeah, it’s a bit lazy to drop the release on you with minimal, if any, commentary from me, but I don’t want to be a gatekeeper of the information being put out and I don’t want to spin the news by selectively writing from a release. With a raw release you get all the information the organization/scientist/whoever put the release out wanted to make public and you can use that information as you see fit. Do keep in mind any release is going to have some manner of bias, even science releases, so read them with that in mind, but do enjoy this exciting news as it comes out.

This release is on nanotechnology and how it is allowing for paper batteries and supercapacitors and is creating a new fabric technology called “eTextiles.”

The release:

Nanotechnology sparks energy storage on paper and cloth

Stanford researcher Yi Cui and his team are re-conceptualizing batteries using nanotechnology

IMAGE: Bing Hu, a post-doctoral fellow in Yi Cui’s research group at Stanford, prepares a small square of ordinary paper with an ink that will deposit nanotubes on the surface that…

Click here for more information.

By dipping ordinary paper or fabric in a special ink infused with nanoparticles, Stanford engineer Yi Cui has found a way to cheaply and efficiently manufacture lightweight paper batteries and supercapacitors (which, like batteries, store energy, but by electrostatic rather than chemical means), as well as stretchable, conductive textiles known as “eTextiles” – capable of storing energy while retaining the mechanical properties of ordinary paper or fabric.

While the technology is still new, Cui’s team has envisioned numerous functional uses for their inventions. Homes of the future could one day be lined with energy-storing wallpaper. Gadget lovers would be able to charge their portable appliances on the go, simply plugging them into an outlet woven into their T-shirts. Energy textiles might also be used to create moving-display apparel, reactive high-performance sportswear and wearable power for a soldier’s battle gear.

The key ingredients in developing these high-tech products are not visible to the human eye. Nanostructures, which can be assembled in patterns that allow them to transport electricity, may provide the solutions to a number of problems encountered with electrical storage devices currently available on the market.

The type of nanoparticle used in the Cui group’s experimental devices varies according to the intended function of the product – lithium cobalt oxide is a common compound used for batteries, while single-walled carbon nanotubes, or SWNTs, are used for supercapacitors.

Cui, an assistant professor of materials science and engineering at Stanford, leads a research group that investigates new applications of nanoscale materials. The objective, said Cui, is not only to supply answers to theoretical inquiries but also to pursue projects with practical value. Recently, his team has focused on ways to integrate nanotechnology into the realm of energy development.

“Energy storage is a pretty old research field,” said Cui. “Supercapacitors, batteries – those things are old. How do you really make a revolutionary impact in this field? It requires quite a dramatic difference of thinking.”

While electrical energy storage devices have come a long way since Alessandro Volta debuted the world’s first electrical cell in 1800, the technology is facing yet another revolution. Current methods of manufacturing energy storage devices can be capital intensive and environmentally hazardous, and the end products have noticeable performance constraints – conventional lithium ion batteries have a limited storage capacity and are costly to manufacture, while traditional capacitors provide high power but at the expense of energy storage capacity.

With a little help from new science, the batteries of the future may not look anything like the bulky metal units we’ve grown accustomed to. Nanotechnology is favored as a remedy both for its economic appeal and its capability to improve energy performance in devices that integrate it. Replacing the carbon (graphite) anodes found in lithium ion batteries with anodes of silicon nanowires, for example, has the potential to increase their storage capacity by 10 times, according to experiments conducted by Cui’s team.

Silicon had previously been recognized as a favorable anode material because it can hold a larger amount of lithium than carbon. But applications of silicon were limited by its inability to sustain physical stress – namely, the fourfold volume increase that silicon undergoes when lithium ions attach themselves to a silicon anode in the process of charging a battery, as well as the shrinkage that occurs when lithium ions are drawn out as it discharges. The result was that silicon structures would disintegrate, causing anodes of this material to lose much if not all of their storage capacity.

Cui and collaborators demonstrated in previous publications in Nature, Nanotechnology and Nano Letters that the use of silicon nanowire battery electrodes, mechanically capable of withstanding the absorption and discharge of lithium ions, was one way to sidestep the problem.

The findings hold promise for the development of rechargeable lithium batteries offering a longer life cycle and higher energy capacity than their contemporaries. Silicon nanowire technology may one day find a home in electric cars, portable electronic devices and implantable medical appliances.

Cui now hopes to direct his research toward studying both the “hard science” behind the electrical properties of nanomaterials and designing real-world applications.

“This is the right time to really see what we learn from nanoscience and do practical applications that are extremely promising,” said Cui. “The beauty of this is, it combines the lowest cost technology that you can find to the highest tech nanotechnology to produce something great. I think this is a very exciting idea … a huge impact for society.”


The Cui group’s latest research on energy storage devices was detailed in papers published in the online editions of the Proceedings of the National Academy of Sciences in December 2009 (“Highly Conductive Paper for Energy-Storage Devices”) and Nano Letters in January 2010 (“Stretchable, Porous and Conductive Energy Textiles”).

Cui’s talk at the symposium “Nanotechnology: Will Nanomaterials Revolutionize Energy Applications?” is scheduled for 9:50 a.m. Feb. 20 in Room 1B of the San Diego Convention Center.

Conductive eTextiles: Stanford finds a new use for cloth

At Stanford, nanotubes + ink + paper = instant battery

February 19, 2010

Broadband Solar offers latest breakthrough

Seems like I’ve been doing a whole lot of solar blogging lately, and here’s the latest breakthrough courtesy of Broadband Solar. This sounds more like an incremental improvement that will possibly lead to commercially viable thin-film solar cells rather than a game-changer ready for market. Even if this announcement doesn’t make it immediately easier or cheaper to put a bank of thin-film cells on the roof of your house, it is one more step toward that goal

From the second link:

Inexpensive thin-film solar cells aren’t as efficient as conventional solar cells, but a new coating that incorporates nanoscale metallic particles could help close the gap. Broadband Solar, a startup spun out of Stanford University late last year, is developing coatings that increase the amount of light these solar cells absorb.

Based on computer models and initial experiments, an amorphous silicon cell could jump from converting about 8 percent of the energy in light into electricity to converting around 12 percent. That would make such cells competitive with the leading thin-film solar cells produced today, such as those made by First Solar, headquartered in Tempe, AZ, says Cyrus Wadia, codirector of the Cleantech to Market Program in the Haas School of Business at the University of California, Berkeley. Amorphous silicon has the advantage of being much more abundant than the materials used by First Solar. The coatings could also be applied to other types of thin-film solar cells, including First Solar’s, to increase their efficiency.

Solar antenna: The square at the center is an array of test solar cells being used to evaluate a coating that contains metallic nanoantennas tuned to the solar spectrum.
Credit: Brongersma lab, Stanford

December 9, 2009

Want a lightweight battery? Try nanotech paper on for size

Filed under: Science, Technology — Tags: , , , — David Kirkpatrick @ 5:02 pm

If this becomes market-ready, it’ll blow the walls off size and weight issues with portable devices. One more amazing use for carbon nanotubes.

From the link:

Ordinary paper can be turned into a battery electrode simply by dipping it into carbon-nanotube inks. The resulting electrodes, which are strong, flexible, and highly conductive, might be used to make cheap energy storage devices to power portable electronics.

It’s now possible to print lightweight circuits and screens for electronics like e-readers, but conventional batteries still weigh these devices down. Carbon nanotubes are a promising material for printing batteries because, in addition to their strength, light weight, and conductivity, they can store a large amount of energy–a quality that helps portable electronics run longer between charges.

Now a group of Stanford University researchers, led by materials science professor Yi Cui, have demonstrated that ordinary office paper soaks up carbon nanotubes like a sponge and can be turned into electrodes for batteries and supercapacitors. The advantage of paper, says Cui, is that it’s cheap and interacts strongly with nanotubes without the need for putting additives in the ink. “We take advantage of the porous structure of paper,” says Cui. “Carbon nanotubes absorb into the paper and stick on really tightly.”

November 13, 2009

Biodegradable organic transistors

Via KurzweilAI.net — This may prove to be a major medical breakthrough once some practical applications get into actual practice and spur on additional innovation.

Biodegradable Transistors
Technology Review, Nov. 13, 2009

Fully biodegradable organic transistors have been fabricated by researchers at Stanford University.

They could be used to control temporary medical implants placed in the body during surgery, and help monitor the healing process from inside the body.


Read Original Article>>

October 29, 2009

Einstein-1, physicist detractors-0

I’ll let this release speak, so to speak, for itself:

Gamma-ray photon race ends in dead heat; Einstein wins this round

IMAGE: In this illustration, one photon (purple) carries a million times the energy of another (yellow). Some theorists predict travel delays for higher-energy photons, which interact more strongly with the proposed…

Click here for more information.


Racing across the universe for the last 7.3 billion years, two gamma-ray photons arrived at NASA’s orbiting Fermi Gamma-ray Space Telescope within nine-tenths of a second of one another. The dead-heat finish may stoke the fires of debate among physicists over Einstein’s special theory of relativity because one of the photons possessed a million times more energy than the other.

For Einstein’s theory, that’s no problem. In his vision of the structure of space and time, unified as space-time, all forms of electromagnetic radiation – gamma rays, radio waves, infrared, visible light and X-rays – are reckoned to travel through the vacuum of space at the same speed, no matter how energetic. But in some of the new theories of gravity, space-time is considered to have a “shifting, frothy structure” when viewed at a scale trillions of times smaller than an electron. Some of those models predict that such a foamy texture ought to slow down the higher-energy gamma-ray photon relative to the lower energy one. Clearly, it did not.

Even in the world of high-energy particle physics, where a minute deviation can sometimes make a massive difference, nine-tenths of a second spread over more than 7 billion years is so small that the difference is likely due to the detailed processes of the gamma-ray burst rather than confirming any modification of Einstein’s ideas.

“This measurement eliminates any approach to a new theory of gravity that predicts a strong energy-dependent change in the speed of light,” said Peter Michelson, professor of physics at Stanford University and principal investigator for Fermi’s Large Area Telescope (LAT), which detected the gamma-ray photons on May 10. “To one part in 100 million billion, these two photons traveled at the same speed. Einstein still rules.”

Michelson is one of the authors of a paper that details the research, published online Oct. 28 by Nature.

Physicists have yearned for years to develop a unifying theory of how the universe works. But no one has been able to come up with one that brings all four of the fundamental forces in the universe into one tent. The Standard Model of particle physics, which was well developed by the end of the 1970s, is considered to have succeeded in unifying three of the four: electromagnetism; the “strong force” (which holds nuclei together inside atoms); and the “weak force” (which is responsible for radioactive decay, among other things.) But in the Standard Model, gravity has always been the odd man out, never quite fitting in. Though a host of theories have been advanced, none has been shown successful.

But by the same token, Einstein’s theories of relativity also fail to unify the four forces.

“Physicists would like to replace Einstein’s vision of gravity – as expressed in his relativity theories – with something that handles all fundamental forces,” Michelson said. “There are many ideas, but few ways to test them.”

The two photons provided rare experimental evidence about the structure of space-time. Whether the evidence will prove sufficient to settle any debates remains to be seen.

The photons were launched on their pan-galactic marathon during a short gamma-ray burst, an outpouring of radiation likely generated by the collision of two neutron stars, the densest known objects in the universe.

A neutron star is created when a massive star collapses in on itself in an explosion called a supernova. The neutron star forms in the core as matter is compressed to the point where it is typically about 10 miles in diameter, yet contains more mass than our sun. When two such dense objects collide, the energy released in a gamma-ray burst can be millions of times brighter than the entire Milky Way, albeit only briefly. The burst (designated GRB 090510) that sent the two photons on their way lasted 2.1 seconds.


NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

January 30, 2009

Stanford researchers write in nanoscale

And reclaim their lost title for writing in the “world’s smallest letters.”

The release:

Stanford writes in world’s smallest letters

Storing information in electron waves

IMAGE: This is an electron wave quantum hologram displaying the initials “SU ” of Stanford University. The yellow area is a copper surface. The holes in the copper are molecules of carbon monoxide….

Click here for more information. 

Stanford researchers have reclaimed bragging rights for creating the world’s smallest writing, a distinction the university first gained in 1985 and lost in 1990.

How small is the writing? The letters in the words are assembled from subatomic sized bits as small as 0.3 nanometers, or roughly one third of a billionth of a meter.

The researchers encoded the letters “S” and “U” (as in Stanford University) within the interference patterns formed by quantum electron waves on the surface of a sliver of copper. The wave patterns even project a tiny hologram of the data, which can be viewed with a powerful microscope.

IMAGE: These are physics grad student Chris Moon (left), Physics Professor Hari Manoharan and physics grad student Laila Mattos worked on the subatomic writing project.

Click here for more information. 

“We miniaturized their size so drastically that we ended up with the smallest writing in history,” said Hari Manoharan, the assistant professor of physics who directed the work of physics graduate student Chris Moon and other researchers.

The quest for small writing has played a role in the development of nanotechnology for 50 years, beginning decades before “nano” became a household word. During a now-legendary talk in 1959, the remarkable physicist Richard Feynman argued that there were no physical barriers preventing machines and circuitry from being shrunk drastically. He called his talk “There’s Plenty of Room at the Bottom.”

Feynman offered a $1,000 prize for anyone who could find a way to rewrite a page from an ordinary book in text 25,000 times smaller than the usual size (a scale at which the entire contents of the Encyclopedia Britannica would fit on the head of a pin). He held onto his money until 1985, when he mailed a check to Stanford grad student Tom Newman, who, working with electrical engineering Professor Fabian Pease, used electron beam lithography to engrave the opening page of Dickens’ A Tale of Two Cities in such small print that it could be read only with an electron microscope.

That record held until 1990, when researchers at a certain computer company famously spelled out the letters IBM by arranging 35 individual xenon atoms.

Now, in a paper published online in the journal Nature Nanotechnology, the Stanford researchers describe how they have created letters 40 times smaller than the original prize-winning effort and more than four times smaller than the IBM initials. (http://www.youtube.com/watch?v=j3QQJEHuefQ)

Working in a vibration-proof basement lab in the Varian Physics Building, Manoharan and Moon began their writing project with a scanning tunneling microscope, a device that not only sees objects at a very small scale but also can be used to move around individual atoms. The Stanford team used it to drag single carbon monoxide molecules into a desired pattern on a copper chip the size of a fingernail.

On the two-dimensional surface of the copper, electrons zip around, behaving as both particles and waves, bouncing off the carbon monoxide molecules the way ripples in a shallow pond might interact with stones placed in the water.

The ever-moving waves interact with the molecules and with each other to form standing “interference patterns” that vary with the placement of the molecules.

By altering the arrangement of the molecules, the researchers can create different waveforms, effectively encoding information for later retrieval. To encode and read out the data at unprecedented density, the scientists have devised a new technology, Electronic Quantum Holography.

In a traditional hologram, laser light is shined on a two-dimensional image and a ghostly 3-D object appears. In the new holography, the two-dimensional “molecular holograms” are illuminated not by laser light but by the electrons that are already in the copper in great abundance. The resulting “electronic object” can be read with the scanning tunneling microscope.

Several images can be stored in the same hologram, each created at a different electron wavelength. The researchers read them separately, like stacked pages of a book. The experience, Moon said, is roughly analogous to an optical hologram that shows one object when illuminated with red light and a different object in green light.

For Manoharan, the true significance of the work lies in storing more information in less space. “How densely can you encode information on a computer chip? The assumption has been that basically the ultimate limit is when one atom represents one bit, and then there’s no more room—in other words, that it’s impossible to scale down below the level of atoms.

“But in this experiment we’ve stored some 35 bits per electron to encode each letter. And we write the letters so small that the bits that comprise them are subatomic in size. So one bit per atom is no longer the limit for information density. There’s a grand new horizon below that, in the subatomic regime. Indeed, there’s even more room at the bottom than we ever imagined.”

In addition to Moon and Manoharan, authors of the Nature Nanotechnologypaper, “Quantum Holographic Encoding in a Two-Dimensional Electron Gas,” are graduate students Laila Mattos, physics; Brian Foster, electrical engineering; and Gabriel Zeltzer, applied physics.

The research was supported by the Department of Energy through SLAC National Accelerator Laboratory and the Stanford Institute for Materials and Energy Science (SIMES), the Office of Naval Research, the National Science Foundation and the Stanford-IBM Center for Probing the Nanoscale.





Video: The World’s Smallest Writing http://www.youtube.com/watch?v=j3QQJEHuefQ

Stanford News Service story: Reading the fine print takes on a new meaning http://news-service.stanford.edu/news/2009/january28/small-012809.html

MANOHARAN LAB http://mota.stanford.edu

RICHARD FEYNMAN’S 1959 NANOTECHNOLOGY TALK http://www.its.caltech.edu/~feynman/plenty.html

NATURENEWS STORY http://www.nature.com/news/2009/090124/full/news.2009.54.html

December 8, 2008

Program for the Future going on right now

From KurzweilAI.netProgram for the Future: A Summit & Workshop on Collective Intelligence is going on right now at the Tech Museum of Innovation, Adobe and Stanford University.

Program For The Future explores collective intelligence
KurzweilAI.net, Dec. 8, 2008Program for the Future: A Summit & Workshop on Collective Intelligence, to be held December 8th – 9th
conference at the Tech Museum of Innovation, Adobe and Stanford University, aims to discover the best new Collective Intelligence tools through a global competition and enhance our capability for problem-solving, decision-making and knowledge organization.

The event will also allow for virtual attendance, including an online video stream and asking questions (limited registration).

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August 23, 2008

New online tool for investors

Here’s the release on a study published the Journal of Consumer Research:

How much risk can you handle? Making better investment decisions

Many Americans make investment decisions with their retirement funds. But they don’t always make informed judgments. A new study in the Journal of Consumer Research introduces a new tool that investors can use to choose investments based on their financial goals and risk attitudes.

Authors Daniel G. Goldstein (London Business School), Eric J. Johnson (Columbia University), and William F. Sharpe (Stanford University) developed a tool, which they call the Distribution Builder. With brief training, people can use the Distribution Builder to better understand their investment goals and trade-offs.

“We think that the Distribution Builder can function like a flight simulator, allowing investors to explore the outcomes of their decisions with only virtual outcomes,” write the authors.

The Distribution Builder is an online tool that estimates the level of risk a user considers unacceptable in his or her investments by using a probability distribution. Since many employees make retirement investment decisions without understanding the complex picture of their own risk preferences, the Distribution Builder is a novel way for people to uncover their preexisting preferences. And, according to the researchers, it can also help people construct better preferences.

The researchers claim that by using the tool, investors can become more actively involved in the process of deciding where and how much to invest. They also believe investment management companies could use the tool to better serve their investors.

The Distribution Builder may have applications that reach beyond retirement investments. “Beyond financial services, the basic DB framework could be used to study other consumer choices in which there is a risk-reward tradeoff, including waiting times at health clinics (or on customer support lines), delivery times of packages, and overage charges for mobile-phone plans,” they conclude.



Daniel G. Goldstein, Eric J. Johnson, and William F. Sharpe. “Choosing Outcomes Versus Choosing Products: Consumer-Focused Retirement Investment Advice” Journal of Consumer Research: October 2008.

July 23, 2008

Maybe tobacco isn’t all that evil after all …

Filed under: Science — Tags: , , , , , , — David Kirkpatrick @ 5:03 pm

… since there seems to be a therapeutic use in treating certain types of cancer. I’m all for tobacco use in moderation, particularly in the form of long-cut filler cigar or high end pipe tobacco. I’ve even blogged on the joys of pipe smoking here, here, here and here.

From KurzweilAI.net:

Tobacco ‘could help treat cancer’
BBC News, July 21, 2008Stanford University researchers are using tobacco plants to grow key components of a cancer vaccine, turning the plants into factories for an antibody chemical specific to the cancerous cells that cause follicular B-cell lymphoma, a type of non-Hodgkin’s lymphoma.

Once a patient’s cancer cells are isolated in the laboratory, the gene responsible for producing the antibody is extracted and added to a tobacco virus. When the virus infects the tobacco, the gene is added to the plants’ cells, which start producing large quantities of the antibody. These antibodies are put back into a patient to “prime” the body’s immune system to attack any cell carrying them.

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