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Nanochip raises funding, challanges flash - Up to 100GB per chip
Nanochip, Inc., a Silicon Valley startup, has managed to raise $14 million in funding from Intel Capital, Intel's global investment organization, for further development of the MEMS technology.
You read it right: gigabytes, not gigabits.
According to Nanochip, the technology isn't lithography constrained, allowing production of chips of more than 1GB in capacity, in plants that have already been deemed outdated by current standards.
The lack of lithography constraints means cheaper products, resulting in an opportunity to also replace flash memory, as the technology is also non-volatile.
Today's factories should be able to produce the first products, estimated at 100GB per chip, when the technology is expected to be unleashed for public consumption by 2010. The first samples will be available during 2009.
PRAM or phase change memory was expected to be the technology to replace flash in the coming years, since it is also non-volatile, while it is much faster than flash. PRAM, though, doesn't seemed to scale so well, in regards to density, and still has some boundaries to overcome, namely it's thermal principles of operation.
The interesting tidbit is this, as taken from the same PRAM wikipedia:
In August of 2004, Nanochip licensed PRAM technology for use in MEMS (micro-electric-mechanical-systems) probe storage devices.
These devices are not solid state. Instead, a very small platter coated in chalcogenide is dragged beneath many (thousands or even millions)
of electrical probes which can read and write the chalcogenide. Hewlett-Packard's micro-mover technology can accurately position
the platter to 3 nanometers so densities of more than 1 terabit per square inch will be possible if the technology can be perfected.
Nanochip is using some kind hybrid PRAM technology in it's MEMS technology, although we don't know, yet, what this means in practical terms -
it could mean a fast access speed.
Access speed is a place where PRAM is appointed to be the undisputed king of the hill, so it could limit applications of this type of technology.
The density claim seems to be right on since 1Tb is approximately 116GB.
For now it seems that the flash SSD drives are going to be replaced before they even reach mass consumption - which is a good thing. The technology is expensive, doesn't provide a lot of storage space and is prone to failure, due to the low amount of write cycles available per cell. Flash is perfect for pendrives and resisting shock, not so good for regular, intensive, HDD usage.

http://www.siliconmadness.com/2008/0...hallanges.html

The full press report is here, below...

Nanochip Raises $14 Million to Complete Development
of Ultra-High-Capacity Removable Data Storage Chips
Series C2 Funding to Support Prototype Development, Design Verification and Sampling
of Removable Chips for Computer, Server and Consumer Electronics Markets
Nanochip, Inc., a developer of advanced microelectromechanical
systems (MEMS) silicon data storage chips, today announced the
completion of a $14 million financing round. In conjunction with Intel Capital and JK&B
Capital, both investors in earlier rounds, this round was led by an additional world-class
investment company. The financing round will allow Nanochip to complete development
of its first prototypes later this year to support design verification testing and limited
customer sampling in 2009.
Nanochip is developing a new class of ultra-high-capacity storage chips enabling the
storage of tens of gigabytes (GB) of data per chip, or the equivalent of many highdefinition
feature-length videos. By coupling MEMS with nano-probe array technology
that far exceeds the expected limits of conventional lithography used in present
semiconductor memory, these new chips are designed to meet the growing demand for
cost-effective, removable and rewritable data storage for use in a wide range of
computing, server and consumer electronics products.
Nanochip’s first products are expected to exceed 100 GB per chip set, reaching
terabytes (TB) in the future, and at a substantially lower cost compared with flash memory solutions.
“Flash has become the technology of choice for a variety of consumer and business
applications where cost-effective, non-volatile solid-state storage is a must,” said Keith
Larson, vice president and director of manufacturing, memory and digital health sectors
for Intel Capital. “However, as flash process technology scaling begins to approach its
limits, Nanochip’s technology is well positioned to provide memory capacity with
exponentially higher storage densities at a cost per gigabyte significantly below that of
flash technology. New memory components, such as Nanochip’s, will enable new,
innovative electronics devices and increase the performance of existing computing and
other devices.”
Nanochip Series C2 Announcement

Page 2 of 2
“Nanochip continues to make significant progress in the development of its ultra-highcapacity
storage chips, and we are delighted to continue to support its development and
commercialization efforts,” said Al DaValle, JK&B Capital partner and member of the
Nanochip board of directors. “Nanochip is poised to help usher in a technological shift
from conventional flash-based storage and micro-sized hard disk drives to ultra-highcapacity
MEMS-based memory devices.”
“This support from leading players within the investment community underscores the
strength of our technology, business model and hard work,” said Gordon R. Knight,
Ph.D., CEO of Nanochip, Inc. “We are well on track to meet our original schedule of
reaching full commercialization of our first product offering by 2010.”
Nanochip has been granted seven U.S. patents for its technology, and has applied for
34 more.
About Nanochip
Nanochip, Inc. (www.nanochipinc.com) was formed in 1996 to develop MEMS storage
chips for consumer electronic applications. The company's products address the need
for low-power, very high-capacity, high-performance, non-volatile memory at a price very
competitive in consumer markets. Nanochip is a private company headquartered in
Fremont, Calif.
About Intel Capital
Intel Capital, Intel's global investment organization, makes equity investments in
innovative technology start-ups and companies worldwide. Intel Capital invests in a
broad range of companies offering hardware, software and services targeting enterprise,
home, mobility, health, consumer Internet, semiconductor manufacturing, and cleantech.
Since 1991, Intel Capital has invested more than US$6 billion in approximately 1,000
companies in more than 40 countries. In that timeframe, about 157 portfolio companies
have gone public on various exchanges around the world and another 187 have been
acquired by other companies. In 2007, Intel Capital invested about US$639 million in
166 deals with approximately 37 percent of funds invested outside the United States.
For more information on Intel Capital and its differentiated advantages, visit
www.intel.com/capital.
About JK&B Capital
JK&B Capital (www.jkbcaptial.com) is a venture capital firm focused in the software, IT
and communications markets with over $900 million of capital under management.
Founded in 1996, JK&B has built a track record of generating exceptional returns for
investors by identifying and investing in companies with technologies which have been
critical to the growth of the world’s information economy.


http://www.nanochipinc.com/NanoChip_...ouncement_.pdf

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...they're complete bullsh*t."

Schneier, author of the books Applied Cryptography, Secrets and Lies and Beyond Fear and described by outgoing Linux Australia president Jonathan Oxer as "a walking security advisor on the entire human race", told a sold-out keynote audience that IT security planning is rarely effective because it fails to take into account the emotional considerations involved in security.
Most security products either address perceived gaps in security and provide an emotional sense of stability without actually doing much useful, or solve actual problems but don't impart the same sense of security, he suggested.
"You can feel secure even though you're not, and you can be secure even though you don't feel it," Schneier said.
"Making security trade-offs is something we do multiple times a day," he noted. "You'd expect human beings would be really good at making these trade-offs, but fundamentally we're hopelessly bad at it." The reason for that, he said, is that "we respond to the feeling of security rather than the reality".
Evolution means that pattern will be difficult to reverse, Schneier argued. "Our society is evolving faster than our species. Modern times are harder. Technology makes it harder, and the media makes it harder."
"People make the trade-off based on the feeling of security, not the reality. The economic incentives are for companies to make people feel secure. That's where you are rewarded in the market."
Drawing on George Akerlof's "lemons market" theory on the economics of information asymetry, Schneier said: "In markets where the seller knows a lot more than the buyer, bad products drive out good products -- and this is very much the case for security."
One notable problem, said Schneier, is the return on investment calculations for security software, which often draw on rare and devastating events to justify their cost: an approach which renders basic mathematics of little use.
"In IT, there isn't a lot of data -- this is one of the problems we have. You have to rely on emotion because we don't have the data. It's very hard to evaluate non-functional requirements."
Understanding of fundamental security principles also needs to dramatically improve, Schneier said.
"We know very little about software security. We can't even prove a program terminates, let alone that it's secure. We don't have a rigorous security methodology. It's going to be a long time before it can be applied to programs and systems and anything resembling actual commercial size."


http://www.zdnet.com.au/news/softwar...ed=pt_security

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Researchers at Idaho National Laboratory, along with partners at Microcontinuum Inc. (Cambridge, MA) and Patrick Pinhero of the University of Missouri, are developing a novel way to collect energy from the sun with a technology that could potentially cost pennies a yard, be imprinted on flexible materials and still draw energy after the sun has set.
The new approach, which garnered two 2007 Nano50 awards, uses a special manufacturing process to stamp tiny square spirals of conducting metal onto a sheet of plastic. Each interlocking spiral "nanoantenna" is as wide as 1/25 the diameter of a human hair.

Because of their size, the nanoantennas absorb energy in the infrared part of the spectrum, just outside the range of what is visible to the eye. The sun radiates a lot of infrared energy, some of which is soaked up by the earth and later released as radiation for hours after sunset. Nanoantennas can take in energy from both sunlight and the earth's heat, with higher efficiency than conventional solar cells.
"I think these antennas really have the potential to replace traditional solar panels," says physicist Steven Novack, who spoke about the technology in November at the National Nano Engineering Conference in Boston.
Taking antennas to the atomic level

An array of nanoantennas, printed in gold and imaged with a scanning
electron microscope. The deposited wire is roughly a thousand atoms thick.
A flexible panel of interconnected nanoantennas may one day
replace heavy, expensive solar panels.
The miniscule circuits absorb energy just like the antenna on your television or in your cell phone. All antennas work by resonance, the same self-reinforcing physical phenomenon that allows a high note to shatter glass. Radio and television antennas must be large because of the wavelength of energy they need to pick up. In theory, making antennas that can absorb electromagnetic radiation closer to what we can see is simple: just engineer a smaller antenna.
An array of nanoantennas, printed in gold and imaged with a scanning electron microscope. The deposited wire is roughly a thousand atoms thick. A flexible panel of interconnected nanoantennas may one day replace heavy, expensive solar panels.
But finding an efficient way to stamp out arrays of atom-scale spirals took a number of years. "It's not that this concept is new," Novack says, "but the boom in nanotechnology is what has really made this possible." The INL team envisions the antennas might one day be produced like foil or plastic wrap on roll-to-roll machinery. So far, they have demonstrated the imprinting process with six-inch circular stamps, each holding more than 10 million antennas.
It wasn't immediately obvious the structures might be used for solar power. At first, the researchers considered pairing the antennas with conventional solar cells to make them more efficient. "Then we thought to start from scratch," Novack says. "We realized we could make the antennas into their own energy harvesters."
An economical alternative
Commercial solar panels usually transform less that 20 percent of the usable energy that strikes them into electricity. Each cell is made of silicon and doped with exotic elements to boost its efficiency. "The supply of processed silicon is lagging, and they only get more expensive," Novack says. He hopes solar nanoantennas will be a more efficient and sustainable alternative.
The team estimates individual nanoantennas can absorb close to 80 percent of the available energy. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that's commonly used in bags and plastic wrap. In fact, the team first printed antennas on plastic bags used to deliver the Wall Street Journal, because they had just the right thickness.
By focusing on readily available materials and rapid manufacturing from inception, Novack says, the aim is to make nanoantenna arrays as cheap as inexpensive carpet.

INL researchers Dale Kotter (left), Steven Novack, and Judy Partin are
developing flexible plastic sheets of nanoantennas to collect solar energy.

Fine-tuning fine structures
The real trick to making the solar nanoantenna panels is to be able to predict their properties and perfect their design before printing them in the factory. While it is relatively easy to work out the physics of one resonating antenna, complex interactions start to happen when multiple antennas are combined. When hit with the right frequency of infrared light, the antennas also produce high-energy electromagnetic fields that can have unexpected effects on the materials.
So the researchers are developing a computer model of resonance in the tiny structures, looking for ways to fine-tune the efficiency of an entire array by changing factors like materials and antenna shape. "The ability to model these antennas is what's going to make us successful, because we can't see these things," Novack says. "They're hard to manipulate, and small tweaks are going to make big differences."
A charged future
One day, Novack says, these nanoantenna collectors might charge portable battery packs, coat the roofs of homes and, perhaps, even be integrated into polyester fabric. Double-sided panels could absorb a broad spectrum of energy from the sun during the day, while the other side might be designed to take in the narrow frequency of energy produced from the earth's radiated heat.
While the nanoantennas are easily manufactured, a crucial part of the process has yet to be fully developed: creating a way to store or transmit the electricity. Although infrared rays create an alternating current in the nanoantenna, the frequency of the current switches back and forth ten thousand billion times a second. That's much too fast for electrical appliances, which operate on currents that oscillate only 60 times a second. So the team is exploring ways to slow that cycling down, possibly by embedding energy conversion devices like tiny capacitors directly into the antenna structure as part of the nanoantenna imprinting process.
"At this point, these antennas are good at capturing energy, but they're not very good at converting it," says INL engineer Dale Kotter, "but we have very promising exploratory research under way." Kotter and Novack are also exploring ways to transform the high-frequency alternating current (AC) to direct current (DC) that can be stored in batteries. One potential candidate is high-speed rectifiers, special diodes that would sit at the center of each spiral antenna and convert the electricity from AC to DC. The team has a patent pending on a variety of potential energy conversion methods. They anticipate they are only a few years away from creating the next generation of solar energy collectors.


http://www.inl.gov/featurestories/2007-12-17.shtml

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Scientists say the results represent a new stage in synthetic biology.


In a technical tour de force, scientists at the J. Craig Venter Institute, in Rockville, MD, have synthesized the genome of the bacterium Mycoplasma genitalium entirely from scratch.
The feat is a stepping stone in creating precisely engineered microbial machines capable of generating biofuels and performing other useful functions.
"It really is groundbreaking that you can synthetically build a genome for a bacterium," says Chris Voigt, a synthetic biologist at the University of California, San Francisco, who was not involved in the project. "It's bigger by orders of magnitude than what's been done before."
Biologists creating genetically engineered organisms now routinely order pieces of DNA that are 10,000 to 20,000 base pairs long--big enough to incorporate the genes for a single metabolic pathway. That allows researchers to engineer microbes that can perform specific tasks, but the ability to synthesize entire genomes could grant a whole new level of control over biological design.
In the new study, scientists ordered 101 DNA fragments, encompassing the entire Mycoplasma genome, from commercial DNA synthesis companies. These fragments were designed so that each overlapped its neighboring sequence by a small amount; these overlapping stretches stick together, thanks to the chemical properties of DNA. Researchers then bound the fragments piece by piece, eventually generating the full 582,970 base pair Mycoplasma sequence. The findings were published Thursday in the online edition of Science.
"We consider this a second and significant step in a three-step process of our attempt to create the first synthetic organism," says Craig Venter, president of the Venter Institute. Venter and his colleagues ultimately want to create a minimal genome--one with the least number of genes needed to sustain life. Pinpointing the minimal genome will both shed light on key cellular processes and provide a base for designing sophisticated synthetic organisms. "We ultimately want to design cells that could function in a robust fashion to make unique biofuels," says Venter.
The researchers' next step will be to show that the synthetic genome functions as it should. "We have the whole genome assembled in a tube, but we need to transplant it into the cell of a different species to show that it can reboot the cell," says Hamilton Smith, a Nobel laureate who oversaw the project at the Venter Institute. Last year, Smith's group transplanted the genome of one species of Mycoplasma into another, demonstrating that this type of transplant is possible.
While the synthesis of a genome might be impressive from a scientific perspective, it is not yet a practical way to engineer microbes to make biofuels. Instead, several companies, including Synthetic Genomics, a biotech company founded by Venter to engineer microbes for energy, are using more traditional metabolic engineering techniques to generate fuel-producing bacteria. "What we're doing with synthetic chromosomes will be the design process for the future," says Venter.
Others in the field are excited about that prospect. "Being able to synthesize genomes opens up a new world," says Voigt. "You can build things on the scale of the genome." For example, he says, scientists are now engineering bacteria to perform different steps in the conversion of biomass into ethanol--one strain to break down the biomass, another to make ethanol. But ideally, scientists could put those processes together to create one organism that could eat biomass and spit out fuel. "That would require genome-scale design," Voigt says.
He likens the current project, which required multiple steps to glue the fragments together, to the last computers designed before automated manufacturing and microfabrication techniques were introduced. Similar advances are needed for more ambitious genome-synthesis projects. "We still need to develop 'one step' genome construction methods in order to reduce the costs and turn time of genome construction," says Drew Endy, a synthetic biologist at MIT.


http://www.technologyreview.com:80/B...0112/?nlid=841

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Nanoptek, a startup based in Maynard, MA, has developed a new way to make hydrogen from water using solar energy. The company says that its process is cheap enough to compete with the cheapest approaches used now, which strip hydrogen from natural gas, and it has the further advantage of releasing no carbon dioxide.
Nanoptek, which has been developing the new technology in part with grants from NASA and the Department of Energy (DOE), recently completed its first venture-capital round, raising $4.7 million that it will use to install its first pilot plant. The technology uses titania, a cheap and abundant material, to capture energy from sunlight. The absorbed energy releases electrons, which split water to make hydrogen. Other researchers have used titania to split water in the past, but Nanoptek researchers found a way to modify titania to absorb more sunlight, which makes the process much cheaper and more efficient, says John Guerra, the company's founder and CEO.

Solar gases: A parabolic trough can focus
sunlight on nanostructured titania, improving
the efficiency of a new system for generating
hydrogen by splitting water.
Credit: John Guerra, Nanoptek

Researchers have known since the 1970s that titania can catalyze reactions that split water. But while titania is a good material because it's cheap and doesn't degrade in water, it only absorbs ultraviolet light, which represents a small fraction of the energy in sunlight. Other researchers have tried to increase the amount of sunlight absorbed by pairing titania with dyes or dopants, but dyes aren't nearly as durable as titania, and dopants haven't produced efficient systems, says John Turner, who develops hydrogen generation technologies at the National Renewable Energy Laboratory (NREL), in Golden, CO.
Nanoptek's approach uses insights from the semiconductor industry to make titania absorb more sunlight. Guerra says that chip makers have long known that straining a material so that its atoms are slightly pressed together or pulled apart alters the material's electronic properties. He found that depositing a coating of titania on dome-like nanostructures caused the atoms to be pulled apart. "When you pull the atoms apart, less energy is required to knock the electrons out of orbit," he says. "That means you can use light with lower energy--which means visible light" rather than just ultraviolet light.
The strain on the atoms also affects the way that electrons move through the material. Too much strain, and the electrons tend to be reabsorbed by the material before they split water. Guerra says that the company has had to find a balance between absorbing more sunlight and allowing the electrons to move freely out of the material. Nanoptek has also developed cheaper ways to manufacture the nanostructured materials. Initially, the company used DVD manufacturing processes, but it has since moved on to a still-cheaper proprietary process.
NREL's John Turner says that Nanoptek's process is "very, very promising." And Harriet Kung, the acting director of the DOE's office of basic energy sciences, which has funded Nanoptek's work, says that the strained-titania approach is "one of the major exciting advances" since titania was first discovered to be a photocatalyst in the 1970s.
If it works as expected, the technology could help address one of the fundamental problems with using hydrogen as fuel. Hydrogen is attractive because it is light, and burning it only produces water. But today most hydrogen is made from natural gas, a process that releases considerable amounts of carbon dioxide. The other main option is electrolysis. But even if it's powered by clean energy, such as electricity from photovoltaics, electrolysis is inefficient and expensive. Guerra says using strained titania, and Nanoptek's inexpensive manufacturing process, makes the process cheap and efficient enough to compete with processes that create hydrogen from natural gas. What's more, Guerra says, the Nanoptek technology can be located closer to customers than large-scale natural-gas processes, which could significantly reduce transportation costs, thereby helping make the technology attractive. And if in the future carbon emissions are taxed or regulated, Nanoptek's carbon-free approach is another advantage.
Turner says that in addition to making hydrogen for fuel-cell vehicles, Nanoptek's process--if it is indeed efficient and inexpensive, as the company claims--could also be important for large-scale solar electricity. If solar is ever to be a dominant source of power, finding ways of storing the energy for night use will be essential. And hydrogen, he says, could be a good way to store it.



http://www.technologyreview.com:80/B...0112/?nlid=841

***

Nanoptek Technology
In the electrolysis process, electricity passed between two electrodes immersed in a water and salt electrolyte dissociates the water into pure hydrogen and oxygen. Commercial electrolyzers require expensive distilled water, and of course electricity.
Replacing one of the electrodes with a photoactive semiconductor such as titania produces hydrogen directly when illuminated with sunlight. This process is known as photolysis, and the device is photoelectrochemical (PEC). Sunlight produces electron-hole charge pairs in the titania that break water (H2O) into hydrogen and oxygen in a reduction-oxidation, or redox, reaction. However, the lifetime and efficiency of PEC technology to date are not commercially viable, and production is either too expensive or is not scalable.

Nanoptek has developed a titania photoelectrode that is low cost, has a long lifetime, and higher efficiency in converting sunlight into hydrogen. Nanoptek has developed a way to use nano-structures (as shown in our logo) to cause large local nano-scale stresses in the titania. This stretches the titania crystal lattice so that electrons are held less tightly in the lattice and so can be knocked out of the titania with light of lower energy, meaning visible. These electrons then drive the hydrogen production. This is known as “bandgap engineering” and causes Nanoptek’s titania photocatalyst to be photoactive well into the visible blue, and so is 6X more efficient in sunlight than native titania, which requires the sparse ultraviolet (UV) part of the solar spectrum.
That this is achieved without dyes or doping results in an inert, robust, and long-lived product. Further, the performance of Nanoptek’s titania improves with heat, so heat from the sun can be used to further increase the efficiency of the photolysis process, and solar concentrators can be used for better economics. Finally, the manufacturing process is scalable, low cost, and requires less energy than other processes.

http://www.nanoptek.com/technology.html

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Research says:

If humans had see-through skin like a jellyfish, spotting disease like cancer would be a snap: Just look, and see a tumor form or grow.
But humans, of course, are not remotely diaphanous. "The reason a person is not transparent is that their tissues are highly scattering," sending light waves careening through the tissue instead of straight through, as they would through the tissue of that jellyfish, explains Changhuei Yang of the California Institute of Technology.
This scattering, in addition to rendering all of us opaque, makes the detection of disease a much trickier issue, requiring a host of diagnostic tests and procedures. But not, perhaps, for much longer, thanks to a new optical trick developed by Yang, an assistant professor of electrical engineering and bioengineering, and his colleagues, that counteracts the scattering of light and removes the distortion it creates in images.
A study describing the process appears in the February issue of the journal Nature Photonics.
It is well known that light scattering in a material is not exactly the random and unpredictable process one might imagine. In fact, scattering is deterministic, which means that the path that a beam of light takes as it traverses a particular slice of tissue and bounces and rebounds off of individual cells, is entirely predictable; if you again bounce light through that same swath of cells, it will scatter in exactly the same way.
The process is even reversible; if the individual photons of light that scattered through the tissue could be collected and sent back through the tissue, they'd bounce back along the same path and converge at the original spot from which they were sent. "The process is similar to the scattering of billiard balls on a pool table. If you can precisely reverse the paths and velocities of the billiard balls, you can cause the billiard balls to reassemble themselves into a rack," Yang explains.
Yang, along with his colleagues at Caltech, École Polytechnique Fédérale de Lausanne in Switzerland, and MIT, exploited this phenomenon to offset the murky nature of our tissues.
Their technique, called turbidity suppression by optical phase conjugation (TSOPC), is surprisingly simple. The scientists used a holographic crystal to record the scattered light pattern emerging from a 0.46-mm-thick piece of chicken breast. They then holographically played the pattern back through the tissue section to recover the original light beam. "This is similar to grabbing hold of the direction of time flow and turning it around; the time-reversed photons must retrace their trajectories through the tissue," Yang says. "The task is formidable though, as this is comparable to starting with a rack of 10 to the 18th power billiard balls (or photons), scattering them around the table, and attempting to reassemble them into a rack."
"Until we did this study, it wasn't clear that the effect will be observable with biological tissues. We were pleasantly surprised that the effect was readily observable and remarkably robust," Yang says. "This study opens up numerous possibilities in the use of optical time reversal in biomedicine."
One possible use of the technique is in photodynamic therapy, in which a highly focused beam of light is aimed at cancerous cells that have absorbed cell-killing light-sensitive compounds. When the light hits the cells, the compounds are activated and destroy the cells. Photodynamic therapy is most effective in treating cancers on the skin surface. Yang's technique, however, offers a way to concentrate light onto cancer-killing compounds located more deeply within tissue.
Yang's idea is to inject strongly light-scattering particles that are coated with light-activated cancer-killing drugs into diseased tissue. Shine a beam of light into the tissue, and it would be reflected off the scattering compounds as it bounces through the tissue. Some of the scattered light would return to the source, where it could be recorded as a hologram.
This hologram would contain information about the path that the scattered light took through the tissue, and, in effect, describe the optimal path BACK toward the light-scattering molecule--and the cancer-killing compounds. Playing back the signal with a stronger burst of light will then activate the therapeutic drugs, which kill the cancer cells.
In addition, the technique could offer a way to power miniature implants buried deep within tissues. "If you take a quick survey of what is out there at present, you will see that implants are fairly large," Yang says. "For example, a pacemaker is about the size of a cell phone. Why are they so big? A large part of the reason is because they need to carry their own power sources."
The key to making smaller implants, then--say, the size of a pen tip--is to eliminate the power sources. "I think implants that carry photovoltaic receivers are particularly promising," he says. "The effect can be applied to tailor light-delivery mechanisms to efficiently channel light into tissues and onto these implants."
Zahid Yaqoob, a postdoctoral fellow in electrical engineering at Caltech, performed most of the experiments reported in the paper. The other authors of the paper are Demetri Psaltis, professor of optics and dean of engineering, École Polytechnique Fédérale de Lausanne in Switzerland, and Michael S. Feld, a professor of physics at MIT


http://mr.caltech.edu/media/Press_Releases/PR13097.html

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A new life-cycle assessment of photovoltaic technologies shows that some are better than others.

New photovoltaic technologies, such as the recent introduction of thin-film cadmium–telluride (CdTe) materials, have nearly doubled the efficiency of solar cells within the past few years. But the methods of making the materials used for photovoltaic cells, whether from silicon, metal, or other material, have raised doubts about the environmental friendliness of these passive energy collectors. Purifying and producing silicon uses a lot of water and energy, and refining zinc and copper ores to get Cd, Te, and other elements creates metal emissions and an energy sink—all of which increase the technology's environmental footprint.
A new life-cycle assessment (LCA) of some of the leading photovoltaic technologies, published in ES&T (DOI: 10.1021/es071763q), shows that some may be better than others, particularly when it comes to emissions over their lifetimes. Overall, however, replacing traditional electricity grids fueled by gas, coal, and other means with photovoltaics would cut emissions of greenhouse gases, particulate matter, and other pollutants by 89–98%. Rooftop panels could further reduce emissions because of the resulting decrease in transmission lines and other infrastructure. But each form of photovoltaics has a different LCA profile, specific to heavy-metal emissions and electricity use in particular, the new analysis shows.
Led by Vasilis Fthenakis of Brookhaven National Laboratory and Columbia University, the LCA includes information from databases of more than a dozen active solar companies and provides a complex snapshot of the state of the solar industry up to 2006. Fthenakis and co-workers compared data from companies that make single-crystal, multicrystal, and ribbon silicon solar cells, all of which have different efficiencies in converting sunlight into electricity. They also compared these products with the thin-film CdTe photovoltaic systems manufactured by fast-growing Arizona-based First Solar.
The analysis took into account frames, cables, and other necessary support materials, as well as the energy required for manufacturing under three scenarios, each with a different proportion of electricity coming from coal, natural gas, or other sources. The team based their assumptions on ground-mounted systems under southern European light conditions, over 30-year lifetimes.
In the end, the CdTe photovoltaics came out on top. With more efficient energy conversion and the lowest cost, the technology used less energy and had fewer emissions overall, despite some Cd emissions during the manufacturing process. However, emissions from fossil-fuel-powered electricity dwarfed those Cd emissions by orders of magnitude.
The new assessment is "incredibly useful," says Corinne Reich-Weiser, a graduate student in mechanical engineering at the University of California Berkeley who works part-time for solar manufacturer SolFocus in San Jose, Calif. The work is unique in that it uses up-to-date processing data, she says. And because the assumptions are the same across the board with regard to yearly available sunlight, performance, and energy grids, "you can easily compare" all of the technologies, she adds.
But the origin of the electricity used to manufacture solar cells varies from place to place, Reich-Weiser points out. The current assessment, based on idealized European and U.S. grids, "is not telling you exactly what your impact is if you were to buy them." For example, impacts from components manufactured in China, where the electricity grid is often powered by coal, will differ from those impacts produced by components made in the U.S. or EU. She also notes that emissions from the transportation of those components before production and assembly, such as by rail or truck, are only partly considered. "Depending on the amount of goods transported throughout the supply chain, including every transportation leg may increase estimated greenhouse gas emissions by 30–50%," she says.
Ken Zweibel, president of Colorado-based PrimeStar Solar, notes that even if China were to adopt photovoltaics wholesale, produced entirely with coal-powered electricity, new solar materials would allow products with 30-year lifetimes to make up for those emissions in several years. Plus future technologies could further shift emissions: "The field is changing fast," adds Zweibel, who recently coauthored a "solar grand plan" with Fthenakis in Scientific American.
One component missing from the current analysis, says Fthenakis, is end-of-life and recycling data. "Those studies are not yet completed," he says, but "it's a safe assumption . . . that recycling will make the emissions profile better, [and] the feasibility of recycling is here."
First Solar, whose growth over the past few years has outpaced silicon manufacturers' with its CdTe approach, recently revealed some of the inner workings of its program, which includes investments for collection and recycling whenever a unit is sold. Lisa Krueger, vice president of sustainability for First Solar, says that recycling makes photovoltaics a "truly sustainable energy solution."


http://pubs.acs.org/subscribe/journa...nl_pvlifecycle

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Simultaneous optical and electronic measurements on same molecule

In a study that could lay the foundation for mass-produced single-molecule sensors, physicists and engineers at Rice University have demonstrated a means of simultaneously making optical and electronic measurements of the same molecule.
The research, which is available online, is slated to appear in an upcoming issue of the journal Nano Letters. The experiments were performed on a nanoelectronic device consisting to two tiny electrodes separated by a molecule-sized gap. Using electric current, the researchers measured conduction through single molecules in the gap. In addition, light-focusing properties of the electrodes allowed the researchers to identify the molecule by a unique optical fingerprint.
"We can mass-produce these in known locations, and they have single-molecule sensitivity at room temperature in open air," said study co-author Douglas Natelson, associate professor of physics and astronomy and co-director of Rice's Quantum Magnetism Laboratory (QML). "In principle, we think the design may allow us to observe chemical reactions at the single-molecule level."
While scientists have used electronic and optical instruments to measure single molecules before, Rice's system is the first that allows both simultaneously -- a process known as "multimodal" sensing -- on a single small molecule.
The research sprang from a collaboration between Natelson's group -- where the electrodes were developed -- and Rice's Laboratory for Nanophotonics (LANP), where the simultaneous electronic and optical testing was performed. In research published last year, the two groups explained how the electrodes focus near-infrared light into the molecule-sized gap, increasing light intensity in the gap by as much as a million times. The increased intensity allows the team to collect unique optical signatures for molecules trapped there via a technique called surface enhanced Raman spectroscopy (SERS).
"Our latest results confirm that we have the sensitivity required to measure single molecules," said LANP Director Naomi Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry. "That sensitivity, and the multimodal capabilities of this system, gives us a great tool for fundamental science at the nanoscale."
Daniel Ward, a student in Natelson's research group, built the electrodes from tiny gold wires on silicon wafers and performed the critical measurements. The group specializes in studying the electronic and magnetic properties of nanoscale objects -- particles and devices that are built with atomic precision. The devices are so small they can only be seen with certain types of microscopes, and even those provide unclear pictures at best. Natelson said the new multimodal device gives researchers a much clearer idea of what is going on by combining two different kinds of measurements, electronic and optical.
"Conduction across our electrodes is known to depend on a quantum effect called 'tunneling,'" Natelson said. "The gaps are so small that only one or two molecules contribute to the conduction. So when we get conduction, and we see the optical fingerprint associated with a particular molecule, and they track each other, then we know we're measuring a single molecule and we know what kind of molecule it is. We can even tell when it rotates and changes position."

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http://www.eurekalert.org/pub_releas...-rsm020608.php

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Filtering sounds so wholesome. As with filtered water, Internet filtering backers suggest that their products simply keep the sludge from passing through, and who wants to drink unfiltered sludge? The big difference between the two kinds of filtering is that sludge can't use 128-bit keys and AES encryption to hide its sludgy nature; Internet traffic can. It's a key problem for any Internet filtering regime, including the one being studied right now by AT&T. Once strong encryption is slapped on Internet traffic, the effectiveness of filters drops off dramatically.
At a Washington, DC, tech conference last week, RIAA boss Cary Sherman suggested that Internet filtering was a super idea but that he saw no reason to mandate it. Turns out that was only part of the story, though; Sherman's a sharp guy, and he's fully aware that filtering will prompt an encryption arms race that is going to be impossible to win... unless users somehow install the filtering software on their home PCs or equipment.
Last night, Public Knowledge posted a video clip from the conference that drew attention to Sherman's other remarks on the topic of filtering, and what he has to say is downright amazing: due to the encryption problem, filters may need to be put on end users' PCs.

The issue of encryption "would have to be faced," Sherman admitted after talking about the wonders of filtering. "One could have a filter on the end user's computer that would actually eliminate any benefit from encryption because if you want to hear [the music], you would need to decrypt it, and at that point the filter would work."

This means moving the filter out of the network and onto the edges (local machines), since it's at the edges that decryption and playback occurs. But who would voluntarily install software that would continually scan incoming P2P streams for copyrighted material after that material has been decrypted? Or software that would watch every song you played and tried to figure out if it was legit?
Sherman knows it's a tough sell. "Why would somebody put that on their machine?" he asked rhetorically. "They wouldn't likely want to do that."
No... they wouldn't. But Sherman's idea is that customers install filtering software such as virus scanners all the time because they see a tangible benefit to it. Apparently, they are supposed to realize the same benefit from installing a filter that flags as illegal the very music that they are trying to download.
This is clearly not going to happen, so Sherman has another idea. He appears to suggest installing the filter in a customer's cable or DSL modem, which wouldn't act as anything more than a network filter (the encryption and decryption happens on the PC). There's also some talk of putting the filtering tech into "applications" such as P2P apps, but again, this seems unlikely, especially for the open-source ones. Maybe he hopes to get OS vendors on board?
The entire scheme has about as much chance of success as my 2008 bid for the White House (write-in Anderson for President in November!). The only way to make it work is to mandate the filters or have ISPs mandate that users install them to get on the Internet. The consumer backlash from such a plan would be like the force of a thousand supernovas, and it's hard to visualize this happening.
What's most incredible about all of this is that the RIAA and some ISPs (namely AT&T) are seriously moving ahead with a filtering regime despite their own admissions that it won't work. Filters might work, they might allow for fair use, and they could conceivably be built in such a way as to maintain privacy, but it just wouldn't matter. Filtering as a concept is ultimately doomed by encryption unless the "filters" simply block entire protocols altogether, and talking about the consumer benefits of installing RIAA-approved filtering software is just another sign of how ludicrous the entire debate has become.


http://arstechnica.com/news.ars/post...n-problem.html

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Budding technologies seek to turn kinetic energy created by the human body into electricity for battery-powered devices

Exercise may soon do more for you than tighten up your sagging muscles. Advances in biomechanical engineering could use energy generated while walking, hiking or running to power any device requiring portable power, including night-vision goggles and other battery-operated devices used by soldiers as well as robotic prosthetic limbs, cell phones and computers in remote locations where no other energy sources are available.
A team of researchers at the Simon Fraser University (S.F.U.) Locomotion Laboratory in Burnaby, British Columbia, are studying the amount of energy that can be generated by 3.5-pound (1.6-kilogram) aluminum and steel knee braces worn while walking or running. Volunteers, wearing a brace strapped on each leg, generated about five watts of electricity per person during a recent experiment, enough power, researchers say, to run 10 cell phones concurrently and twice that needed to keep a computer running (something useful in developing regions of Africa where electricity is scarce). They report that one brace-wearing subject generated 54 watts of power by running in place.

The best area to place a device for harnessing human energy is near a joint, because this is where the muscles—the body's power source—work hardest, says Max Donelan, Locomotion Lab director and an assistant professor at S.F.U.'s School of Kinesiology. "There's a long history of human power generation using hand cranks and bikes, but these require your dedicated attention, so you don't do it for very long." The key to energy harvesting is extracting the energy from the body's natural movement and, aside from breathing, very few unconscious muscle movements are more automatic than the action of walking.
Donelan and his team of researchers targeted a particular part of the stride, halfway through the swing of the lower leg after it has left the ground (when the hamstring comes to life to make sure you don't have uncontrolled extension) through the time the foot returns to the ground. The brace designed to capture this energy features gears, a clutch, a generator and a computerized control system that monitors the knee's angle to determine when to engage and disengage power generation.
The specific amount of energy generated from Donelan's device depends upon the weight of the wearer, the difficulty of the terrain, the speed of the person's gait and how long the device is used. In the prototype, energy generated is dissipated into resistors, although future models could include an onboard battery for energy storage. The researchers hope to be able to test their device within a year on Canadian soldiers at a field site.
Another effort underway to convert motion into energy relies on the Faraday law of induction, named after English chemist and physicist Michael Faraday, which holds that the movement of a conductor (such as a metal wire) through a magnetic field produces a voltage in that conductor proportional to the speed of movement. M2E Power, Inc., in Boise, Idaho, has developed a system of magnets and coils that, when moved, generates energy that can be used to power their host device. M2E's technology originated at the Idaho National Laboratory, a Department of Energy–funded research group.
A good example of this would be walking with a cell phone in your front pocket or attached to your belt. The phone's movement would cause the magnet and coil to generate energy that could be transferred to a bank of ultracapacitors that charge the phone's battery when a certain voltage level is reached. "Think of it as a minigenerator whose power comes from movement," says Regan Warner-Rowe, M2E's director of business development. "Because power management is such a critical issue for cell phones, we have been in discussions with handset companies." (Warner-Rowe declined to name them.)
Another goal of M2E's research and development is to develop technology that could be used by the U.S. military. (The Australian army is working with contractors to develop its own wearable, rechargeable battery system, as well.) Much like Donelan's work, the objective is to eliminate several pounds of weight that soldiers must lug around in the form of spare batteries. M2E has done some work developing prototype energy-rechargeable "D" cell batteries.


http://www.sciam.com/article.cfm?id=...-phone-battery

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Natural flyers like birds, bats and insects outperform man-made aircraft in aerobatics and efficiency. University of Michigan engineers are studying these animals as a step toward designing flapping-wing planes with wingspans smaller than a deck of playing cards.

A Blackbird jet flying nearly 2,000 miles per hour covers 32 body lengths per second. But a common pigeon flying at 50 miles per hour covers 75. The roll rate of the aerobatic A-4 Skyhawk plane is about 720 degrees per second. The roll rate of a barn swallow exceeds 5,000 degrees per second.
Select military aircraft can withstand gravitational forces of 8-10 G. Many birds routinely experience positive G-forces greater than 10 G and up to 14 G.
“Natural flyers obviously have some highly varied mechanical properties that we really have not incorporated in engineering,” said Wei Shyy, chair of the Aerospace Engineering department and an author of the new book “The Aerodynamics of Low Reynolds Number Flyers.”
“They’re not only lighter, but also have much more adaptive structures as well as capabilities of integrating aerodynamics with wing and body shapes, which change all the time,” Shyy said. “Natural flyers have outstanding capabilities to remain airborne through wind gusts, rain, and snow.” Shyy photographs birds to help him understand their aerodynamics.
Pressure generated during flight cause the flapping wings to deform, he explained. In turn, the deformed wing tells the air that the wing shape is different than it appears in still air. If appropriately handled, this phenomenon can delay stall, enhance stability and increase thrust.
Flapping flight is inherently unsteady, but that’s why it works so well. Birds, bats and insects fly in a messy environment full of gusts traveling at speeds similar to their own. Yet they can react almost instantaneously and adapt with their flexible wings.
Shyy and his colleagues have several grants from the Air Force totaling more than $1 million a year to research small flapping wing aircraft. Such aircraft would fly slower than their fixed wing counterparts, and more importantly, they would be able to hover and possibly perch in order to monitor the environment or a hostile area. Shyy’s current focus is on the aerodynamics of flexible wings related to micro air vehicles with wingspans between 1 and 3 inches.
“These days, if you want to design a flapping wing vehicle, you could build one with trial and error, but in a controlled environment with no wind gusts,” Shyy said. “We are trying to figure out how to design a vehicle that can perform a mission in an uncertain environment. When the wind blows, how do they stay on course?”
A dragonfly, Shyy says, has remarkable resilience to wind, considering how light it is. The professor chalks that up to its wing structure and flight control. But the details are still questions.
“We’re really just at the beginning of this,” Shyy said.
Shyy is the Clarence L. "Kelly" Johnson Collegiate Professor of Aerospace Engineering. Other authors of the book, “Aerodynamics of Low Reynolds Number Flyers” are: U-M research scientists Yongsheng Lian, Jian Tang and Dragos Viieru, and Hao Liu, professor of Biomechanical Engineering at Chiba University in Japan.
Other collaborators on this research include professors Luis Bernal, Carlos Cesnik and Peretz Friedmann of the University of Michigan; Hao Liu of Chiba University in Japan; Peter Ifju, Rick Lind and Larry Ukeiley of University of Florida, and Sean Humbert of University of Maryland.

http://www.sciencedaily.com/releases...0204172203.htm

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A California company reported today that it has, for the first time, cloned human embryos using DNA from adult skin cells. That's "an important first step" toward generating embryonic stem (ES) cell lines from such embryos, which can be used to study and treat diseases such as diabetes and Parkinson's, says stem cell researcher George Daley of Harvard Medical School in Boston.
Scientists want to be able to clone early human embryos, using cells from patients with various diseases, so they can study the diseases in the lab and develop new treatments for them. A major breakthrough occurred last year when scientists figured out how to turn skin cells into ES-like cells that could serve the same purpose. But they still want to be able to do cloning, otherwise known as somatic cell nuclear transfer (SCNT), because embryonic cells are the "gold standard" for pluripotent cells--cells that can become any cell type in the body. In addition, scientists want to learn more about how an oocyte can reprogram a mature cell back into an ES cell.

Promising growth.
(Clockwise from left)
Three-, 5-, and 6-day-old cloned embryos.
Credit: A. French et al., Stem Cells (17 January 2008)

In the new study, a research team at Stemagen, a biotech company based in San Diego, California, started with skin cells donated by two men and 25 eggs, or oocytes, donated by women at a nearby fertility center. The scientists removed the DNA-containing nuclei from the eggs and replaced them with DNA from the donor skin cells. Two of the eggs became 5-day-old embryos, or blastocysts, that were clones of the male donors. That's an "unexpectedly high" success rate, the company said in a statement.
Study leader Andrew French says the key to the team's success was utilizing fresh, mature oocytes from females of proven fertility. "We wanted to access the best raw material," he says. The researchers have also worked with "fail-to-fertilize" eggs discarded from fertility clinics, French says, but these "don't develop--they basically fall apart eventually."
The advance, published online today in the journal Stem Cells, comes less than 2 months after researchers succeeded in generating ES cells from cloned monkey blastocysts--the first time this has been achieved with primates. Both papers mark something of a comeback for the field, which was shaken 2 years ago by revelations about fraudulent research by Korean scientist Woo Suk Hwang. Mindful of suspicions remaining from the Hwang disaster, the group sent their blastocysts to a separate company to verify the genetic composition. DNA fingerprinting confirmed that two of the blastocysts had the DNA of the male donor cells. In another test, researchers verified that a third had the mitochondrial DNA but no nuclear DNA from the oocyte, indicating that that, too, was a clone. For technical reasons, the genetic makeup of the remaining two couldn't be verified, although the company believes that they are also clones.
Although scientists have welcomed the development, they say the real breakthrough will be when someone manages to extract ES cells from the inner cell mass of cloned blastocysts and generate a cell line from them. That's the only way to get ES cells with the genetic signatures of patients whose diseases they want to study.
Stemagen's team says that's next, but Robert Lanza of Advanced Cell Technology in Worcester, Massachusetts, doubts the researchers could do it with the embryos they have created so far. "There is a large body of data ... showing that [SCNT] leads to chromosomal abnormalities," he says. The blastocysts in the paper "look very unhealthy," says Lanza. "I would guess these clones are abnormal, too." French counters that the director of the clinic that provided the eggs "says she has got pregnancies from IVF [in vitro fertilization] embryos that look similar."
Meanwhile, another advance on the cloning front occurred yesterday in the United Kingdom, where two research teams have at long last gained permission from the government to culture "hybrid" embryos from injecting human DNA into cow or rabbit eggs. The researchers want to use these to study reprogramming without resorting to using hard-to-get human eggs.


http://sciencenow.sciencemag.org/cgi...ull/2008/117/1

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V-Frog, the world’s first virtual-reality-based frog dissection software designed for biology education -- allowing not mere observation, but physically simulated dissection -- has been developed and is being marketed by Tactus Technologies.

“Other products out there are multi-media, not true virtual reality,” explains Kevin P. Chugh, Ph.D. ’01, president and chief scientist at Tactus Technologies, based in Getzville, a northern suburb of Buffalo.
V-Frog, which operates on a personal computer using a standard mouse, actually simulates nearly unlimited manipulation of specimen tissue. As a result, every dissection is different, reflecting each student’s individual work. The software is designed for grades 7 through 12, plus advanced placement biology students.
Using a simple mouse and PC, students can “pick up” a scalpel, cut open V-Frog’s skin, and explore the internal organs -- with true real-time interaction and 3-D navigation that actually accommodates discovery and procedures not possible with a physical frog specimen.
“You can go through the entire alimentary canal, using the endoscopic function -- something you could never do with a real frog,” says Chugh. “Likewise, with our V-Frog, you can explore nerves and blood vessels, and look closely at how the brain is wired. Students would never get the opportunity to see and work with these things this way with a real frog.”
Life-like V-Frog, which was in development for three years, uniquely allows for comparative anatomy, letting students make parallels and contrasts between the amphibian’s physiology and that of a human being, crab and other organisms. In addition, V-Frog allows students to watch a beating heart, observe digestion, dissect, probe and perform endoscopic procedures.
“With other products, it’s just a video -- static and two-dimensional,” Chugh explains. “This is a simulation product, not simply a static Web site. It’s actually superior to physical specimens and multi-media representations. The technology allows for virtual surgery. Our tissue simulation lets students see the correlation between form and function, and can be manipulated however the student wishes. It’s truly a physically simulated dissection.”
The Humane Society of the United States, as well as educators, legislators, students and others, support the realization that the use of virtual-reality frog dissection means no exposure to chemicals and potentially dangerous instruments, no specimen or ecosystem harm and no specimen disintegration.
“This is very much a sign of the times,” declares Chugh, noting that at least 25 states have laws or ordinances mandating that, if dissection is part of a school’s curriculum, students must have an alternative to dissection. “It’s a mainstream reality.”
Additionally, the use of V-Frog means students are not constrained to a lab environment. The state-of-the-art product complies with both inquiry and life science standards. Instructors can also model a dissection, observable by the entire class, using a projector. This teaching and learning experience can be conveniently repeated as often as desired.
V-Frog passed an important milestone when California approved V-Frog for legal and social compliance as per their State board of Education guidelines. It is also in the final stages of a similar review in New York State. According to Chugh, V-Frog’s simulated dissection is more economical than real dissection due to its one-time license cost versus annual replacement of real frogs, dissection supplies and chemicals.


http://www.physorg.com/news121749911.html

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A seagoing glider that harvests heat energy from the ocean to propel itself is being used to explore the undersea environment off Puerto Rico, say US researchers.

They said the glider had crisscrossed the 4000-meter-deep Virgin Islands Basin between Saint Thomas Island and Saint Croix Island east of Puerto Rico more than 20 times since it was launched in December 2007. See a video of the glider in action (28 MB, .avi).
And it could keep going on its own for another 6 months, the team at the Woods Hole Oceanographic Institution and Webb Research Corporation in Massachusetts, US, predicts.
Instead of using motors and propellers, underwater gliders propel themselves by altering their buoyancy. Still, most gliders use internal motors to adjust their centre of mass by pumping water or oil between the craft's pressurised inner hull and its outer one.
Hot waxThe new glider instead harnessed the temperature difference at different depths. Warmer surface waters heat wax-filled tubes, expanding the wax, and creating mechanical power driving internal pumps. Cooler water at lower depths reverses the process.
In future, such robots could autonomously monitor ocean conditions, carrying sensors that measure temperature, salinity and biological activity. They would only need to surface occasionally to fix their position using the Global Positioning System and to communicate via satellite to a laboratory.
"Gliders can be put to work on tasks that humans wouldn't want to do or cannot do because of time and cost concerns," says Dave Fratantoni of Woods Hole. "We are tapping a virtually unlimited energy source for propulsion."
Fratantoni adds that data collected by the gliders could help researchers understand how eddies in the region affect ocean circulation and disperse the larvae of fish, as well as pollutants. "They can work around the clock in all weather conditions," he says.

http://technology.newscientist.com/c...ine-news_rss20

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An implantable device that releases precise doses of a drug into a patient's bloodstream at the flick of a switch is a step closer with prototype technology demonstrated by US scientists.Paula Hammond and colleagues at Massachusetts Institute of Technology, US, developed a drug-infused film that breaks down when a voltage is applied across its surface.The technology promises greater control at lower cost than alternative approaches to precision drug delivery, the researchers say.The new film could be used to coat an implantable powered device that would release medication on command. Applying a small voltage from the device to the film causes it to break down and release its drug. Turning the voltage off again stops the film dissolving.The researchers used nanoparticles of a pigment called Prussian blue – an inorganic iron hexacyanoferrate compound – to make the film and a chemical called dextran sulphate to represent the drug in their prototype.Power supplyThey took a glass substrate coated with indium tin oxide and dipped it in a solution containing dextran sulfate, which is positively charged. Next, they dipped the substrate into a solution containing negatively charged Prussian blue nanoparticles.By repeating the process they gradually built up alternating layers of pigment layers and "drug" held together by electrostatic charge.Applying 1.25 volts to the substrate caused the layers to lose their charge and begin dissolving in a solution. When the voltage was removed, the layers stabilised and stopped dissolving.The device could be used to deliver drugs to a specific part of the body, such an area where a tumour had been removed. Or it could deliver a drug needed only under certain conditions, such as anti-seizure medication, Hammond says.Remote controlDrug release could be controlled manually with a remote control or even by a device that monitors conditions in the body and turns itself off and on, she adds.Other researchers have proposed micro-fluidic devices for drug release, but Hammond believes her approach is cheaper and simpler."We won't have to use any sort of machining, or any of the more complex micro-fabricating techniques," she told New Scientist. "We can actually generate these thin films, and literally stamp them onto surfaces.""Switching on and off is the key, and something they have done well," says David LaVan, a mechanical engineer at Yale University. "The most significant challenge would be to scale this up to deliver enough drug to justify the use of an implanted device for drug delivery."


http://technology.newscientist.com/c...ine-news_rss20