Site of the day: http://www.nytimes.com/
)
IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is a solar sail which gathers sunlight as propulsion by means of a large sail. This spacecraft was launched May 20, 2010 together with the Akatsuki Venus Climate Orbiter aboard an H-IIA launch vehicle. This solar powered sail craft will employ both photon propulsion and thin film solar power generation during its interplanetary cruise.
The Planetary Society has assembled a page of resources for the press on JAXA's deep-space missions, including IKAROS. For the latest news on IKAROS, visit The Planetary Society Blog.
About IKAROS
Is IKAROS energy-saving?
IKAROS is a satellite to navigate space, deploying a large solar sail. Traditional satellites always needed fuels wherever their destinations were. The asteroid probe Hayabusa was driven by ion engines, which were energy-saving but still needed fuel called xenon gas.
Flyable without fuel, IKAROS is more than energy saving – it requires no energy. IKAROS can both approach to and recede from the Sun with elaborate use of its solar cells and the pressure of sunlight.
How does IKAROS fly?
Earth makes one revolution a year around the sun. The Earth's orbit around the sun is constant because the centrifugal force produced by the earth's orbital motion and the force of the sun's gravity are balanced. What would happen if Earth slowed down in its orbit? Earth would get closer to the Sun as the centrifugal force weakened. The same dynamics apply to IKAROS.
Imagine that IKAROS is orbiting the Sun at the same speed and in the same orbit as Earth. If IKAROS speeds up, with its large sail inclined toward the Sun, it will start moving away from the sun, heading outward toward the orbit of Mars. But, if it slows down, it will start falling downward to the Sun and approach to the orbit of Venus.
What is IKAROS' destination?
IKAROS is planned to approach Venus' orbit after a six-month flight. Then, it will travel, relying only on the solar force, until it reaches the far side of the Sun three years after launch.
What does IKAROS look like?
At launch, it has a fat, short cylindrical shape. A polyamide sail is wound tightly around it. The sail is designed to be deployed in space by centrifugal force produced by rotation of the satellite itself.
(http://www.planetary.org/explore/topics/ikaros/)
Read also:
IKAROS Begins Attitude Control by Louis Friedman
http://www.planetary.org/blog/article/00002567/
Lou Friedman in Japan: IKAROS sail deployment proceeding
http://www.planetary.org/blog/article/00002523/
Saturday, July 3, 2010
Sunday, June 20, 2010
Nano Design, Just Like in Nature
Site of the day: http://www.bloomberg.com/
ScienceDaily (June 15, 2010) — Researchers at Vienna University of Technology (TU Vienna) are using biological principles as the inspiration to develop a new bionic fuel cell.
Every living cell in our body can do it: covered with a thin membrane known as a cell membrane or nanomembrane, the cells can deliberately let specific substances in and out. Although it is thousands of times thinner than a human hair, this nanomembrane has an extremely complex structure and function. Three Nobel prizes have already been awarded for improving our understanding of these nanomembranes.
Microscopic ducts convey water, electrical charges and nutrients around and in doing so, create an equilibrium within the cell. However, we still do not know about many of the functions and structural details, as it is only the water and proton exchange that has been researched in depth. "These extremely fine cell membrane ducts, with the ability to selectively convey protons, function in exactly the same way as fuel cells created by humans," explains Dr Werner Brenner, "only this naturally occurring process is considerably more efficient."
Fuel cells: an alternative to oil
Today, fuel cells are seen as a serious alternative to oil, which until now has been the basis for electrical energy and mobility. However, the earth's oil reserves are rapidly running out, under economic pressure to drill ever deeper into the seabed. Oil combustion also generates CO2, soot and other residues. The only waste product from a fuel cell is water.
The EU project focuses on the design of the main component of every fuel cell -- i.e. the membrane -- with the intention of conveying protons more efficiently than in previous solutions. "The first results have been encouraging. It will not be easy, but it is possible. Nature has been producing these structures for billions of years and their effectiveness can be seen in every living organism. Our task is to transfer the structure of these natural nanoducts to an artificial nanomembrane, which is itself only a few hundred nanometres thick," explains Dr Jovan Matovic.
A wide range of scientific approaches are required for this project, ranging from solid state physics and nanotechnology through to chemistry. Therefore, international cooperation with six universities, research institutes and businesses is also of great importance. The EU project is being coordinated by the TU Vienna research team of Assist Prof Dr Werner Brenner, Dr Jovan Matovic and Dr Nadja Adamovic at the Institute of Sensor and Actuator Systems.
The University research team is confident: "The results of this project should have far-reaching significance for our society. If we succeed in creating the nanoducts exactly as planned, then completely different fields of application will open up, such as the accurately controlled delivery of medicine, water desalination or even new types of sensors," explains Dr Nadja Adamovic, "In this project, the boundaries between "artificial and "natural" are becoming even more blurred."
(http://www.sciencedaily.com/releases/2010/06/100615151705.htm)
ScienceDaily (June 15, 2010) — Researchers at Vienna University of Technology (TU Vienna) are using biological principles as the inspiration to develop a new bionic fuel cell.
Every living cell in our body can do it: covered with a thin membrane known as a cell membrane or nanomembrane, the cells can deliberately let specific substances in and out. Although it is thousands of times thinner than a human hair, this nanomembrane has an extremely complex structure and function. Three Nobel prizes have already been awarded for improving our understanding of these nanomembranes.
Microscopic ducts convey water, electrical charges and nutrients around and in doing so, create an equilibrium within the cell. However, we still do not know about many of the functions and structural details, as it is only the water and proton exchange that has been researched in depth. "These extremely fine cell membrane ducts, with the ability to selectively convey protons, function in exactly the same way as fuel cells created by humans," explains Dr Werner Brenner, "only this naturally occurring process is considerably more efficient."
Fuel cells: an alternative to oil
Today, fuel cells are seen as a serious alternative to oil, which until now has been the basis for electrical energy and mobility. However, the earth's oil reserves are rapidly running out, under economic pressure to drill ever deeper into the seabed. Oil combustion also generates CO2, soot and other residues. The only waste product from a fuel cell is water.
The EU project focuses on the design of the main component of every fuel cell -- i.e. the membrane -- with the intention of conveying protons more efficiently than in previous solutions. "The first results have been encouraging. It will not be easy, but it is possible. Nature has been producing these structures for billions of years and their effectiveness can be seen in every living organism. Our task is to transfer the structure of these natural nanoducts to an artificial nanomembrane, which is itself only a few hundred nanometres thick," explains Dr Jovan Matovic.
A wide range of scientific approaches are required for this project, ranging from solid state physics and nanotechnology through to chemistry. Therefore, international cooperation with six universities, research institutes and businesses is also of great importance. The EU project is being coordinated by the TU Vienna research team of Assist Prof Dr Werner Brenner, Dr Jovan Matovic and Dr Nadja Adamovic at the Institute of Sensor and Actuator Systems.
The University research team is confident: "The results of this project should have far-reaching significance for our society. If we succeed in creating the nanoducts exactly as planned, then completely different fields of application will open up, such as the accurately controlled delivery of medicine, water desalination or even new types of sensors," explains Dr Nadja Adamovic, "In this project, the boundaries between "artificial and "natural" are becoming even more blurred."
(http://www.sciencedaily.com/releases/2010/06/100615151705.htm)
Saturday, May 8, 2010
Faster, Cheaper DNA Sequencing Method Devised
Site of the day: http://fooledbyrandomness.com/
ScienceDaily (Dec. 22, 2009) — Boston University biomedical engineers have devised a method for making future genome sequencing faster and cheaper by dramatically reducing the amount of DNA required, thus eliminating the expensive, time-consuming and error-prone step of DNA amplification.
In a study published in the Dec. 20 online edition of Nature Nanotechnology, a team led by Boston University Biomedical Engineering Associate Professor Amit Meller details pioneering work in detecting DNA molecules as they pass through silicon nanopores. The technique uses electrical fields to feed long strands of DNA through four-nanometer-wide pores, much like threading a needle. The method uses sensitive electrical current measurements to detect single DNA molecules as they pass through the nanopores.
"The current study shows that we can detect a much smaller amount of DNA sample than previously reported," said Meller. "When people start to implement genome sequencing or genome profiling using nanopores, they could use our nanopore capture approach to greatly reduce the number of copies used in those measurements."
Currently, genome sequencing utilizes DNA amplification to make billions of molecular copies in order to produce a sample large enough to be analyzed. In addition to the time and cost DNA amplification entails, some of the molecules -- like photocopies of photocopies -- come out less than perfect. Meller and his colleagues at BU, New York University and Bar-Ilan University in Israel have harnessed electrical fields surrounding the mouths of the nanopores to attract long, negatively charged strands of DNA and slide them through the nanopore where the DNA sequence can be detected. Since the DNA is drawn to the nanopores from a distance, far fewer copies of the molecule are needed.
Before creating this new method, the team had to develop an understanding of electro-physics at the nanoscale, where the rules that govern the larger world don't necessarily apply. They made a counterintuitive discovery: the longer the DNA strand, the more quickly it found the pore opening.
"That's really surprising," Meller said. "You'd expect that if you have a longer 'spaghetti,' then finding the end would be much harder. At the same time this discovery means that the nanopore system is optimized for the detection of long DNA strands -- tens of thousands basepairs, or even more. This could dramatically speed future genomic sequencing by allowing analysis of a long DNA strand in one swipe, rather than having to assemble results from many short snippets.
"DNA amplification technologies limit DNA molecule length to under a thousand basepairs," Meller added. "Because our method avoids amplification, it not only reduces the cost, time and error rate of DNA replication techniques, but also enables the analysis of very long strands of DNA, much longer than current limitations."
With this knowledge in hand, Meller and his team set out to optimize the effect. They used salt gradients to alter the electrical field around the pores, which increased the rate at which DNA molecules were captured and shortened the lag time between molecules, thus reducing the quantity of DNA needed for accurate measurements. Rather than floating around until they happened upon a nanopore, DNA strands were funneled into the openings.
By boosting capture rates by a few orders of magnitude, and reducing the volume of the sample chamber the researchers reduced the number of DNA molecules required by a factor of 10,000 -- from about 1 billion sample molecules to 100,000.
The research was funded by the National Human Genome Research Institute of the Institutes of Health and by the National Science Foundation.
Journal Reference:
Electrostatic Focusing of Unlabelled DNA into Nanoscale Pores Using a Salt Gradient. Nature Nanotechnology, Online December 21, 2009 DOI: 10.1038/natureNNANO.2009.379
(http://www.sciencedaily.com/releases/2009/12/091220143923.htm)
ScienceDaily (Dec. 22, 2009) — Boston University biomedical engineers have devised a method for making future genome sequencing faster and cheaper by dramatically reducing the amount of DNA required, thus eliminating the expensive, time-consuming and error-prone step of DNA amplification.
In a study published in the Dec. 20 online edition of Nature Nanotechnology, a team led by Boston University Biomedical Engineering Associate Professor Amit Meller details pioneering work in detecting DNA molecules as they pass through silicon nanopores. The technique uses electrical fields to feed long strands of DNA through four-nanometer-wide pores, much like threading a needle. The method uses sensitive electrical current measurements to detect single DNA molecules as they pass through the nanopores.
"The current study shows that we can detect a much smaller amount of DNA sample than previously reported," said Meller. "When people start to implement genome sequencing or genome profiling using nanopores, they could use our nanopore capture approach to greatly reduce the number of copies used in those measurements."
Currently, genome sequencing utilizes DNA amplification to make billions of molecular copies in order to produce a sample large enough to be analyzed. In addition to the time and cost DNA amplification entails, some of the molecules -- like photocopies of photocopies -- come out less than perfect. Meller and his colleagues at BU, New York University and Bar-Ilan University in Israel have harnessed electrical fields surrounding the mouths of the nanopores to attract long, negatively charged strands of DNA and slide them through the nanopore where the DNA sequence can be detected. Since the DNA is drawn to the nanopores from a distance, far fewer copies of the molecule are needed.
Before creating this new method, the team had to develop an understanding of electro-physics at the nanoscale, where the rules that govern the larger world don't necessarily apply. They made a counterintuitive discovery: the longer the DNA strand, the more quickly it found the pore opening.
"That's really surprising," Meller said. "You'd expect that if you have a longer 'spaghetti,' then finding the end would be much harder. At the same time this discovery means that the nanopore system is optimized for the detection of long DNA strands -- tens of thousands basepairs, or even more. This could dramatically speed future genomic sequencing by allowing analysis of a long DNA strand in one swipe, rather than having to assemble results from many short snippets.
"DNA amplification technologies limit DNA molecule length to under a thousand basepairs," Meller added. "Because our method avoids amplification, it not only reduces the cost, time and error rate of DNA replication techniques, but also enables the analysis of very long strands of DNA, much longer than current limitations."
With this knowledge in hand, Meller and his team set out to optimize the effect. They used salt gradients to alter the electrical field around the pores, which increased the rate at which DNA molecules were captured and shortened the lag time between molecules, thus reducing the quantity of DNA needed for accurate measurements. Rather than floating around until they happened upon a nanopore, DNA strands were funneled into the openings.
By boosting capture rates by a few orders of magnitude, and reducing the volume of the sample chamber the researchers reduced the number of DNA molecules required by a factor of 10,000 -- from about 1 billion sample molecules to 100,000.
The research was funded by the National Human Genome Research Institute of the Institutes of Health and by the National Science Foundation.
Journal Reference:
Electrostatic Focusing of Unlabelled DNA into Nanoscale Pores Using a Salt Gradient. Nature Nanotechnology, Online December 21, 2009 DOI: 10.1038/natureNNANO.2009.379
(http://www.sciencedaily.com/releases/2009/12/091220143923.htm)
Friday, May 7, 2010
Remote Controlled Robot Performs Heart Surgery on British Man
Site of the day: http://www.wired.com/
May 5th, 2010 by Aaron Saenz
On April 28th, for the first time ever, a British doctor at Leicester’s Glenfield Hospital used a catheter robot to perform heart surgery on a patient while not in the operating room. The Remote Catheter Manipulation System (RCMS), developed by Catheter Robotics in the US, feeds a long thin wire (catheter) from a vein in the patient’s groin up to the heart where it uses electrodes to stimulate and then heal the heart by selectively burning tissue. This operation is used to correct an irregular heartbeat. Typically, the catheter is fed into the body by hand, but the robot allowed surgeon Andre Ng to perform the operation from outside the OR. That’s a great advantage to the doctor as this enabled him to avoid the 250+ X-rays exposures that are used during the operation to monitor inside the patient’s body. The RCMS also helped speed up the process considerably. This success is another sign of the rise in robotic surgery all across the world. We’ve got a great video about the operation for you after the break.
The use of robots in hospitals has been increasing for decades. The DaVinci robot is already used in the vast majority of prostate surgeries in the US. Catherine Mohr, one of the pioneers in the field, has long predicted that they will come to dominate surgeries in the future. All of the systems currently in use are almost completely remote controlled. Some controls are very complex, the DaVinci has a stereoscopic work station and two control arms, while others are fairly simple, Dr. Ng used two buttons to change the direction of the catheter, and thread it into and out the patient. Eventually, however, there will just be one button: “go”. Robots won’t simply turn surgery into a video game, they’ll actually perform the entire operation with a minimum of human guidance.
Many of the headlines surrounding Dr. Ng’s success has referred to this as the “first robotic heart surgery” or some variation thereof. That’s a negligent way of phrasing things. Heart surgeries have been performed using remote controlled robot arms for several years (often via the DaVinci system). In fact, it’s not even the first surgery using a robot catheter. As far as I can tell, what is unique about the Leicester operation was that it was the first using a robotic catheter with such simplified controls and that a surgeon performed this type of correction for arrhythmia while outside the OR.
Despite my frustration at these headlines, this operation still is an important first. Getting surgeons out of the OR not only saves them from risky radiation exposure, it heralds a time when any surgery can be performed by a surgeon located anywhere in the world. After all, Dr. Ng performed the operation via computer monitors and a remote control, he could have easily been in another country as another room (given the appropriate secured internet connection).
While the day of universal robotic surgery is still rather far off, I’m amazed by how relatively cheap and easy it is to use one of these catheter robots. While the price tag may seem steep ($540,000 or £350,000) it’s not outrageously expensive for hospital equipment. Furthermore, doctors already familiar with the catheter operation should be able to convert to the robotic system with a minimum of training because of its simple controls.
The advantages of robot surgery are increasing. These machines allow for surgeries to be performed with small incisions (sometimes only one) rather than opening the entire chest. They can prevent surgeons from receiving repeated exposure to radiation. Robots may also allow for long distance remote control, giving patients a wider range of surgeons to select from. In the end, these advantages are likely to bring more and more robotics into the OR, and robots may become the tool of choice for most surgeries. Eventually the sophistication of these systems will allows them to meet and then exceed the talents of human surgeons in all but the most creative of operations. Dr. Ng’s work saw a remarkable achievement with a procedure performed through a robot. Soon, however, we will see procedures performed by a robot. That, my friends, will be the start of amazing things.
(http://singularityhub.com/2010/05/05/remote-controlled-robot-performs-heart-surgery-on -british-man-video/)
Read also:
http://www.gizmag.com/heart-surgery-rc-robot/14947/
http://spectrum.ieee.org/biomedical/devices/heart-surgeons-adapting-to-robots
May 5th, 2010 by Aaron Saenz
On April 28th, for the first time ever, a British doctor at Leicester’s Glenfield Hospital used a catheter robot to perform heart surgery on a patient while not in the operating room. The Remote Catheter Manipulation System (RCMS), developed by Catheter Robotics in the US, feeds a long thin wire (catheter) from a vein in the patient’s groin up to the heart where it uses electrodes to stimulate and then heal the heart by selectively burning tissue. This operation is used to correct an irregular heartbeat. Typically, the catheter is fed into the body by hand, but the robot allowed surgeon Andre Ng to perform the operation from outside the OR. That’s a great advantage to the doctor as this enabled him to avoid the 250+ X-rays exposures that are used during the operation to monitor inside the patient’s body. The RCMS also helped speed up the process considerably. This success is another sign of the rise in robotic surgery all across the world. We’ve got a great video about the operation for you after the break.
The use of robots in hospitals has been increasing for decades. The DaVinci robot is already used in the vast majority of prostate surgeries in the US. Catherine Mohr, one of the pioneers in the field, has long predicted that they will come to dominate surgeries in the future. All of the systems currently in use are almost completely remote controlled. Some controls are very complex, the DaVinci has a stereoscopic work station and two control arms, while others are fairly simple, Dr. Ng used two buttons to change the direction of the catheter, and thread it into and out the patient. Eventually, however, there will just be one button: “go”. Robots won’t simply turn surgery into a video game, they’ll actually perform the entire operation with a minimum of human guidance.
Many of the headlines surrounding Dr. Ng’s success has referred to this as the “first robotic heart surgery” or some variation thereof. That’s a negligent way of phrasing things. Heart surgeries have been performed using remote controlled robot arms for several years (often via the DaVinci system). In fact, it’s not even the first surgery using a robot catheter. As far as I can tell, what is unique about the Leicester operation was that it was the first using a robotic catheter with such simplified controls and that a surgeon performed this type of correction for arrhythmia while outside the OR.
Despite my frustration at these headlines, this operation still is an important first. Getting surgeons out of the OR not only saves them from risky radiation exposure, it heralds a time when any surgery can be performed by a surgeon located anywhere in the world. After all, Dr. Ng performed the operation via computer monitors and a remote control, he could have easily been in another country as another room (given the appropriate secured internet connection).
While the day of universal robotic surgery is still rather far off, I’m amazed by how relatively cheap and easy it is to use one of these catheter robots. While the price tag may seem steep ($540,000 or £350,000) it’s not outrageously expensive for hospital equipment. Furthermore, doctors already familiar with the catheter operation should be able to convert to the robotic system with a minimum of training because of its simple controls.
The advantages of robot surgery are increasing. These machines allow for surgeries to be performed with small incisions (sometimes only one) rather than opening the entire chest. They can prevent surgeons from receiving repeated exposure to radiation. Robots may also allow for long distance remote control, giving patients a wider range of surgeons to select from. In the end, these advantages are likely to bring more and more robotics into the OR, and robots may become the tool of choice for most surgeries. Eventually the sophistication of these systems will allows them to meet and then exceed the talents of human surgeons in all but the most creative of operations. Dr. Ng’s work saw a remarkable achievement with a procedure performed through a robot. Soon, however, we will see procedures performed by a robot. That, my friends, will be the start of amazing things.
(http://singularityhub.com/2010/05/05/remote-controlled-robot-performs-heart-surgery-on -british-man-video/)
Read also:
http://www.gizmag.com/heart-surgery-rc-robot/14947/
http://spectrum.ieee.org/biomedical/devices/heart-surgeons-adapting-to-robots
Wednesday, April 14, 2010
Memristors
Site of the day: http://molecularstation.com/
H.P. Sees a Revolution in Memory Chip
PALO ALTO, Calif. — Hewlett-Packard scientists on Thursday are to report advances in the design of a new class of diminutive switches capable of replacing transistors as computer chips shrink closer to the atomic scale.
by John Markoff
H.P. Sees a Revolution in Memory Chip
PALO ALTO, Calif. — Hewlett-Packard scientists on Thursday are to report advances in the design of a new class of diminutive switches capable of replacing transistors as computer chips shrink closer to the atomic scale.
The devices, known as memristors, or memory resistors, were conceived in 1971 by Leon O. Chua, an electrical engineer at the University of California, Berkeley, but they were not put into effect until 2008 at the H.P. lab here.
They are simpler than today’s semiconducting transistors, can store information even in the absence of an electrical current and, according to a report in Nature, can be used for both data processing and storage applications.
The researchers previously reported in The Proceedings of the National Academy of Sciences that they had devised a new method for storing and retrieving information from a vast three-dimensional array of memristors. The scheme could potentially free designers to stack thousands of switches in a high-rise fashion, permitting a new class of ultradense computing devices even after two-dimensional scaling reaches fundamental limits.
Memristor-based systems also hold out the prospect of fashioning analog computing systems that function more like biological brains, Dr. Chua said.
“Our brains are made of memristors,” he said, referring to the function of biological synapses. “We have the right stuff now to build real brains.”
In an interview at the H.P. research lab, Stan Williams, a company physicist, said that in the two years since announcing working devices, his team had increased their switching speed to match today’s conventional silicon transistors. The researchers had tested them in the laboratory, he added, proving they could reliably make hundreds of thousands of reads and writes.
That is a significant hurdle to overcome, indicating that it is now possible to consider memristor-based chips as an alternative to today’s transistor-based flash computer memories, which are widely used in consumer devices like MP3 players, portable computers and digital cameras.
“Not only do we think that in three years we can be better than the competitors,” Dr. Williams said. “The memristor technology really has the capacity to continue scaling for a very long time, and that’s really a big deal.”
As the semiconductor industry has approached fundamental physical limits in shrinking the size of the devices that represent digital 1’s and 0’s as on and off states, it has touched off an international race to find alternatives.
New generations of semiconductor technology typically advance at three-year intervals, and today the industry can see no further than three and possibly four generations into the future.
The most advanced transistor technology today is based on minimum feature sizes of 30 to 40 nanometers — by contrast a biological virus is typically about 100 nanometers — and Dr. Williams said that H.P. now has working 3-nanometer memristors that can switch on and off in about a nanosecond, or a billionth of a second.
He said the company could have a competitor to flash memory in three years that would have a capacity of 20 gigabytes a square centimeter.
“We believe that that is at least a factor of two better storage than flash memory will be able to have in that time frame,” he said.
The H.P. technology is based on the ability to use an electrical current to move atoms within an ultrathin film of titanium dioxide. After the location of an atom has been shifted, even by as little as a nanometer, the result can be read as a change in the resistance of the material. That change persists even after the current is switched off, making it possible to build an extremely low-power device.
The new material offers an approach that is radically different from a promising type of storage called “phase-change memory” being pursued by I.B.M., Intel and other companies.
In a phase-change memory, heat is used to shift a glassy material from an amorphous to a crystalline state and back. The switching speed of these systems is slower and requires more power, the H.P. scientists say.
by John Markoff
(http://www.nytimes.com/2010/04/08/science/08chips.html)
http://spectrum.ieee.org/tag/memristor
Wednesday, April 7, 2010
Nanoscale 'Stealth' Probe Slides Into Cell Walls Seamlessly, Say Engineers
A 'stealth' probe sits firmly fused into a cell membrane. The membrane is represented by the small blue spheres, with the hydrophobic portion inside shown by squiggly fine blue lines. The silicon part of the probe is black and the chromium bands that bound the thin gold band are silver-gray. The gold band is obscured by the carbon atoms that are attached to it and that integrate with the hydrophobic part of the membrane. (Credit: Benjamin Almquist)
Site of the day: http://www.wired.com/
ScienceDaily (Apr. 2, 2010) — A nanometer-scale probe designed to slip into a cell wall and fuse with it could offer researchers a portal for extended eavesdropping on the inner electrical activity of individual cells.
Everything from signals generated as cells communicate with each other to "digestive rumblings" as cells react to medication could be monitored for up to a week, say Stanford engineers.
Current methods of probing a cell are so destructive they usually only allow a few hours of observation before the cell dies. The researchers are the first to implant an inorganic device into a cell wall without damaging it.
The key design feature of the probe is that it mimics natural gateways in the cell membrane, said Nick Melosh, an assistant professor of materials science and engineering in whose lab the research was done. With modification, the probe might serve as a conduit for inserting medication into a cell's heavily defended interior, he said. It might also provide an improved method of attaching neural prosthetics, such as artificial arms that are controlled by pectoral muscles, or deep brain implants used for treating depression.
The 600-nanometer-long, metal-coated silicon probe has integrated so smoothly into membranes in the laboratory, the researchers have christened it the "stealth" probe.
"The probes fuse into the membranes spontaneously and form good, strong junctions there," Melosh said. The attachment is so strong, he said, "We cannot pull them out. The membrane will just keep deforming rather than let go of the probes."
Melosh and Benjamin Almquist, a graduate student in materials science and engineering, are coauthors of a paper describing the research published March 30 in Proceedings of the National Academy of Sciences.
Up to now, poking a hole in a cell membrane has largely relied on brute force, Melosh said.
"We can basically rip holes in the cells using suction, we can use high voltage to puncture holes in their membranes, both of which are fairly destructive," he said. "Many of the cells don't survive." That limits the duration of any observations, particularly electrical measurements of cell function.
The key to the probe's easy insertion -- and the membrane's desire to retain it -- is that Melosh and Almquist based its design on a type of protein naturally found in cell walls that acts as a gatekeeper, controlling which molecules are allowed in or out.
A cell membrane is essentially a walled fortress. Within the wall itself is a water-repellant, or hydrophobic, zone. Since almost all molecules in a living being are water soluble, the hydrophobic region acts as a barrier to keep the molecules from slipping through the cell wall. The only way in or out is via the specialized proteins that form bridges across the membrane.
Those "transmembrane" protein gateways match the architecture of the membrane, with a hydrophobic center section bounded by two water soluble, or hydrophilic, layers.
"What we have done is make an inorganic version of one of those membrane proteins, which sits in the membrane without disrupting it," Melosh said. "Now we can envision using it for doing our own gate keeping."
To build their probe, Melosh and Almquist appropriated nanofabrication methods from the semiconductor industry to make tiny silicon posts, the tips of which they coated with three thin layers of metal -- a layer of gold between two of chromium -- to match the sandwich structure of the membrane. They then coated the gold band with carbon molecules to render it hydrophobic; the chromium bands are naturally hydrophilic.
"Getting that hydrophobic band just a few nanometers in thickness was an incredible technical challenge," Melosh said. Applying such a thin layer to the tip of a probe only 200 nanometers in diameter was impossible using existing methods, so he and Almquist devised a new technique using metal deposition to create the thin band that was needed.
That carefully applied metal coating on the stealth probe could give researchers electrical access to the inside of a cell, where they might monitor the electrical impulses generated by various cellular activities, Melosh said. That, combined with the probe's stability in the membrane, could be a huge asset to studies of certain electrically excitable cells such as neurons, which send signals throughout the brain, spinal cord and other nerves.
A device called a "patch clamp" can be used to monitor those sorts of electrical signals among cells now, Melosh said, but in its current form, it is comparatively crude.
"You come in with it, touch it to the cell surface, apply suction and tear a hole in the cell to give you access," he said. "However, it is a fairly slow procedure that has to be done one cell at a time, and it kills the cell within an hour or so."
"If the stealth probe will give us a long-term patch clamp, we'll really be able to get the ability to watch these networks over long periods of time, perhaps up to a week," he said.
"Ideally, what you'd like to be able to do is have an access port through the cell membrane that you can put things in or take things out, measure electrical currents … basically full control," said Melosh. "That's really what we've shown -- this is a platform upon which you can start building those kinds of devices."
The next step is to demonstrate the functionality of the probe in living cells. Almquist and Melosh are now working with human red blood cells and cervical cancer cells, as well as ovary cells from a species of hamster.
Journal Reference:
Almquist et al. Fusion of biomimetic stealth probes into lipid bilayer cores. Proceedings of the National Academy of Sciences, 2010; 107 (13): 5815
DOI: 10.1073/pnas.0909250107
(http://www.sciencedaily.com/releases/2010/04/100401143123.htm)
Sunday, April 4, 2010
Microbes Reprogrammed to Ooze Oil for Renewable Biofuel
Site of the day: http://futurepundit.com/
ScienceDaily (Mar. 29, 2010) — Using genetic sleight of hand, researcher Xinyao Liu and professor Roy Curtiss at Arizona State University's Biodesign Institute have coaxed photosynthetic microbes to secrete oil -- bypassing energy and cost barriers that have hampered green biofuel production. Their results appear in this week's advanced online issue of the Proceedings of the National Academy of Sciences or PNAS.
The challenges of developing a renewable biofuel source that is competitive with the current scalability and low-cost of petroleum have been daunting. "The real costs involved in any biofuel production are harvesting the fuel precursors and turning them into fuel," said Roy Curtiss, director of the Biodesign Institute's Center for Infectious Diseases and Vaccinology and professor in the School of Life Sciences. "By releasing their precious cargo outside the cell, we have optimized bacterial metabolic engineering to develop a truly green route to biofuel production."
Photosynthetic microbes called cyanobacteria offer attractive advantages over the use of plants like corn or switchgrass, producing many times the energy yield with energy input from the sun and without the necessity of taking arable cropland out of production.
Lead author Xinyao Liu and Curtiss, applied their expertise in the development of bacterial-based vaccines to genetically optimize cyanobacteria for biofuel production. Last year, they were able to modify these microbes, priming them to self-destruct and release their lipid contents. In the group's lastest effort however, the energy-rich fatty acids were extracted without killing the cells in the process.
"In China, we have a saying," Liu says. "We don't kill the hen to get the eggs." Rather than destroying the cyanobacteria, the group has ingeniously reengineered their genetics, producing mutant strains that continuously secrete fatty acids through their cell walls. The cyanobacteria essentially act like tiny biofuel production facilities.
Liu realized that if cyanobacteria could be cajoled into overproducing fatty acids, their accumulation within the cells would eventually cause these fatty acids to leak out through the cell membrane, through the process of diffusion. To accomplish this, Liu introduced a specific enzyme, known as thioesterase, into cyanobacteria.
The enzyme is able to uncouple fatty acids from complex carrier proteins, freeing them within the cell where they accumulate, until the cell secretes them. "I use genes that can steal fatty acids from the lipid synthesis pathway," Liu explains noting that thioesterase acts to efficiently clip the bonds associating the fatty acids with more complex molecules. This use of modified thioesterases to cause secretion of fatty acids was first described for Escherichia coli by John Cronan of the University of Illinois more than a decade ago.
A second series of modifications enhances the secretion process, by genetically deleting or modifying two key layers of the cellular envelope -- known as the S and peptidoglycan layers -- allowing fatty acids to more easily escape outside the cell, where their low water solubility causes them to precipitate out of solution, forming a whitish residue on the surface. Study results show a 3-fold increase in fatty acid yield, after genetic modification of the two membrane layers.
To improve the fatty acid production even further, the group added genes to cause overproduction of fatty acid precursors and removed some cellular pathways that were non-essential to the survival of cyanobacteria. Such modifications ensure that the microbe's resources are devoted to basic survival and lipid production.
Liu emphasizes that the current research has moved along at a lightening clip, with only about 6 months passing from the initial work, through production of the first strains -- a fact he attributes to the formidable expertise in the area of microbial genetic manipulation, assembled at the Biodesign Institute. "I don't think any group would have the capacity to do this as fast," he said.
Professor Roy Curtiss agrees, noting that "the seminal advance has been to combine a number of genetic modifications and enzyme activities previously described in other bacteria and in plants in the engineered cyanobacteria strains along with the introduction of newly discovered modifications to increase production and secretion of fatty acids. The results to date are encouraging and we are confident of making further improvements to achieve enhanced productivity in strains currently under construction and development. In addition, optimizing growth conditions associated with scale-up will also improve productivity."
The team, which includes researchers Daniel Brune and Wim Vermaas, is also optimistic that significantly higher fatty acid yields will be obtainable, as research continues.
The research opens the door to practical use of this promising source of clean energy.
(http://www.sciencedaily.com/releases/2010/03/100329152525.htm)
ScienceDaily (Mar. 29, 2010) — Using genetic sleight of hand, researcher Xinyao Liu and professor Roy Curtiss at Arizona State University's Biodesign Institute have coaxed photosynthetic microbes to secrete oil -- bypassing energy and cost barriers that have hampered green biofuel production. Their results appear in this week's advanced online issue of the Proceedings of the National Academy of Sciences or PNAS.
The challenges of developing a renewable biofuel source that is competitive with the current scalability and low-cost of petroleum have been daunting. "The real costs involved in any biofuel production are harvesting the fuel precursors and turning them into fuel," said Roy Curtiss, director of the Biodesign Institute's Center for Infectious Diseases and Vaccinology and professor in the School of Life Sciences. "By releasing their precious cargo outside the cell, we have optimized bacterial metabolic engineering to develop a truly green route to biofuel production."
Photosynthetic microbes called cyanobacteria offer attractive advantages over the use of plants like corn or switchgrass, producing many times the energy yield with energy input from the sun and without the necessity of taking arable cropland out of production.
Lead author Xinyao Liu and Curtiss, applied their expertise in the development of bacterial-based vaccines to genetically optimize cyanobacteria for biofuel production. Last year, they were able to modify these microbes, priming them to self-destruct and release their lipid contents. In the group's lastest effort however, the energy-rich fatty acids were extracted without killing the cells in the process.
"In China, we have a saying," Liu says. "We don't kill the hen to get the eggs." Rather than destroying the cyanobacteria, the group has ingeniously reengineered their genetics, producing mutant strains that continuously secrete fatty acids through their cell walls. The cyanobacteria essentially act like tiny biofuel production facilities.
Liu realized that if cyanobacteria could be cajoled into overproducing fatty acids, their accumulation within the cells would eventually cause these fatty acids to leak out through the cell membrane, through the process of diffusion. To accomplish this, Liu introduced a specific enzyme, known as thioesterase, into cyanobacteria.
The enzyme is able to uncouple fatty acids from complex carrier proteins, freeing them within the cell where they accumulate, until the cell secretes them. "I use genes that can steal fatty acids from the lipid synthesis pathway," Liu explains noting that thioesterase acts to efficiently clip the bonds associating the fatty acids with more complex molecules. This use of modified thioesterases to cause secretion of fatty acids was first described for Escherichia coli by John Cronan of the University of Illinois more than a decade ago.
A second series of modifications enhances the secretion process, by genetically deleting or modifying two key layers of the cellular envelope -- known as the S and peptidoglycan layers -- allowing fatty acids to more easily escape outside the cell, where their low water solubility causes them to precipitate out of solution, forming a whitish residue on the surface. Study results show a 3-fold increase in fatty acid yield, after genetic modification of the two membrane layers.
To improve the fatty acid production even further, the group added genes to cause overproduction of fatty acid precursors and removed some cellular pathways that were non-essential to the survival of cyanobacteria. Such modifications ensure that the microbe's resources are devoted to basic survival and lipid production.
Liu emphasizes that the current research has moved along at a lightening clip, with only about 6 months passing from the initial work, through production of the first strains -- a fact he attributes to the formidable expertise in the area of microbial genetic manipulation, assembled at the Biodesign Institute. "I don't think any group would have the capacity to do this as fast," he said.
Professor Roy Curtiss agrees, noting that "the seminal advance has been to combine a number of genetic modifications and enzyme activities previously described in other bacteria and in plants in the engineered cyanobacteria strains along with the introduction of newly discovered modifications to increase production and secretion of fatty acids. The results to date are encouraging and we are confident of making further improvements to achieve enhanced productivity in strains currently under construction and development. In addition, optimizing growth conditions associated with scale-up will also improve productivity."
The team, which includes researchers Daniel Brune and Wim Vermaas, is also optimistic that significantly higher fatty acid yields will be obtainable, as research continues.
The research opens the door to practical use of this promising source of clean energy.
(http://www.sciencedaily.com/releases/2010/03/100329152525.htm)
Saturday, March 27, 2010
Tunable bipolar optical interactions between guided lightwaves
Site of the day: http://www.wired.com/
Paper.
Authors: Li, Mo ; Pernice, W H P ; Tang, H X
The optical binding forces between guided lightwaves in dielectric waveguides can be either repulsive or attractive. So far only attractive force has been observed. Here we experimentally demonstrate a bipolar optical force between coupled nanomechanical waveguides. Both attractive and repulsive optical forces are obtained. The sign of the force can be switched reversibly by tuning the relative phase of the interacting lightwaves. This tunable, bipolar interaction forms the foundation for the operation of a new class of light force devices and circuits.
Links:
http://www.nature.com/nphoton/journal/v3/n8/abs/nphoton.2009.116.html
http://arxiv.org/ftp/arxiv/papers/0903/0903.5117.pdf
Paper.
Authors: Li, Mo ; Pernice, W H P ; Tang, H X
The optical binding forces between guided lightwaves in dielectric waveguides can be either repulsive or attractive. So far only attractive force has been observed. Here we experimentally demonstrate a bipolar optical force between coupled nanomechanical waveguides. Both attractive and repulsive optical forces are obtained. The sign of the force can be switched reversibly by tuning the relative phase of the interacting lightwaves. This tunable, bipolar interaction forms the foundation for the operation of a new class of light force devices and circuits.
Links:
http://www.nature.com/nphoton/journal/v3/n8/abs/nphoton.2009.116.html
http://arxiv.org/ftp/arxiv/papers/0903/0903.5117.pdf
Light twists rigid structures in unexpected nanotech finding
After 72 hours of exposure to ambient light, strands of nanoparticles twisted and bunched together. Credit: Nicholas Kotov
Site of the day: http://www.wired.com/
ANN ARBOR, Mich.—In findings that took the experimenters three years to believe, University of Michigan engineers and their collaborators have demonstrated that light itself can twist ribbons of nanoparticles.
The results are published in the current edition of Science.
Matter readily bends and twists light. That's the mechanism behind optical lenses and polarizing 3-D movie glasses. But the opposite interaction has rarely been observed, said Nicholas Kotov, principal investigator on the project. Kotov is a professor in the departments of Chemical Engineering, Biomedical Engineering and Materials Science and Engineering.
While light has been known to affect matter on the molecular scale—bending or twisting molecules a few nanometers in size—it has not been observed causing such drastic mechanical twisting to larger particles. The nanoparticle ribbons in this study were between one and four micrometers long. A micrometer is one-millionth of a meter.
"I didn't believe it at the beginning," Kotov said. "To be honest, it took us three and a half years to really figure out how photons of light can lead to such a remarkable change in rigid structures a thousand times bigger than molecules."
Kotov and his colleagues had set out in this study to create "superchiral" particles—spirals of nano-scale mixed metals that could theoretically focus visible light to specks smaller than its wavelength. Materials with this unique "negative refractive index" could be capable of producing Klingon-like invisibility cloaks, said Sharon Glotzer, a professor in the departments of Chemical Engineering and Materials Science and Engineering who was also involved in the experiments. The twisted nanoparticle ribbons are likely to lead to the superchiral materials, the professors say.
To begin the experiment, the researchers dispersed nanoparticles of cadmium telluride in a water-based solution. They checked on them intermittently with powerful microscopes. After about 24 hours under light, the nanoparticles had assembled themselves into flat ribbons. After 72 hours, they had twisted and bunched together in the process.
But when the nanoparticles were left in the dark, distinct, long, straight ribbons formed.
"We discovered that if we make flat ribbons in the dark and then illuminate them, we see a gradual twisting, twisting that increases as we shine more light," Kotov said. "This is very unusual in many ways."
The light twists the ribbons by causing a stronger repulsion between nanoparticles in them.
The twisted ribbon is a new shape in nanotechnology, Kotov said. Besides superchiral materials, he envisions clever applications for the shape and the technique used to create I it. Sudhanshu Srivastava, a postdoctoral researcher in his lab, is trying to make the spirals rotate.
"He's making very small propellers to move through fluid—nanoscale submarines, if you will," Kotov said. "You often see this motif of twisted structures in mobility organs of bacteria and cells."
The nanoscale submarines could conceivably be used for drug-delivery and in microfluidic systems that mimic the body for experiments.
This newly-discovered twisting effect could also lead to microelectromechanical systems that are controlled by light. And it could be utilized in lithography, or microchip production.
Glotzer and Aaron Santos, a postdoctoral researcher in her lab, performed computer simulations that helped Kotov and his team better understand how the ribbons form. The simulations showed that under certain circumstances, the complex combination of forces between the tetrahedrally-shaped nanoparticles could conspire to produce ribbons of just the width observed in the experiments. A tetrahedron is a pyramid-shaped, three-dimensional polyhedron.
"The precise balance of forces leading to the self-assembly of ribbons is very revealing," Glotzer said. "It could be used to stabilize other nanostructures made of non-spherical particles. It's all about how the particles want to pack themselves."
Other collaborators include researchers from the University of Leeds in the UK, Chungju National University in Korea, Argonne National Laboratory, Pusan National University in Korea and Jiangnan University in China.
The paper is titled Light-Controlled Self-Assembly of Semiconductor Nanoparticles into Twisted Ribbons. The research is funded by the Air Force Office of Scientific Research, the Korea Science and Engineering Foundation and the U.S. Department of Energy.
(http://www.ns.umich.edu/htdocs/releases/story.php?id=7573)
Friday, March 5, 2010
Diamonds And Quantum Science
A diamond-based nanowire device. Researchers used a top-down nanofabrication technique to embed color centers into a variety of machined structures. By creating large device arrays rather than just "one-of-a-kind" designs, the realization of quantum networks and systems, which require the integration and manipulation of many devices in parallel, is more likely. Illustrated by Jay Penni.
Site of the day: http://nanotechweb.org/
Digging Deep Into Diamonds, Physicists Advance Quantum Science And Technology
By creating diamond-based nanowire devices, a team at Harvard has taken another step towards making applications based on quantum science and technology possible.
The new device offers a bright, stable source of single photons at room temperature, an essential element in making fast and secure computing with light practical.
The finding could lead to a new class of nanostructured diamond devices suitable for quantum communication and computing, as well as advance areas ranging from biological and chemical sensing to scientific imaging.
Published in the February 14th issue of Nature Nanotechnology, researchers led by Marko Loncar, Assistant Professor of Electrical Engineering at the Harvard School of Engineering and Applied Sciences (SEAS), found that the performance of a single photon source based on a light emitting defect (color center) in diamond could be improved by nanostructuring the diamond and embedding the defect within a diamond nanowire.
Scientists, in fact, first began exploiting the properties of natural diamonds after learning how to manipulate the electron spin, or intrinsic angular momentum, associated with the nitrogen vacancy (NV) color center of the gem. The quantum (qubit) state can be initialized and measured using light.
The color center "communicates" by emitting and absorbing photons. The flow of photons emitted from the color center provides a means to carry the resulting information, making the control, capture, and storage of photons essential for any kind of practical communication or computation. Gathering photons efficiently, however, is difficult since color-centers are embedded deep inside the diamond.
"This presents a major problem if you want to interface a color center and integrate it into real-world applications," explains Loncar. "What was missing was an interface that connects the nano-world of a color center with macro-world of optical fibers and lenses."
The diamond nanowire device offers a solution, providing a natural and efficient interface to probe an individual color center, making it brighter and increasing its sensitivity. The resulting enhanced optical properties increases photon collection by nearly a factor of ten relative to natural diamond devices.
"Our nanowire device can channel the photons that are emitted and direct them in a convenient way," says lead-author Tom Babinec, a graduate student at SEAS.
Further, the diamond nanowire is designed to overcome hurdles that have challenged other state-of-the-art systems—such as those based on fluorescent dye molecules, quantum dots, and carbon nanotubes—as the device can be readily replicated and integrated with a variety of nano-machined structures.
The researchers used a top-down nanofabrication technique to embed color centers into a variety of machined structures. By creating large device arrays rather than just "one-of-a-kind" designs, the realization of quantum networks and systems, which require the integration and manipulation of many devices in parallel, is more likely.
"We consider this an important step and enabling technology towards more practical optical systems based on this exciting material platform," says Loncar. "Starting with these synthetic, nanostructured diamond samples, we can start dreaming about the diamond-based devices and systems that could one day lead to applications in quantum science and technology as well as in sensing and imaging."
(http://www.physorg.com/news185372725.html)
Other articles:
http://www.popularmechanics.co.za/content/news/singlepage.asp?key=926
http://www.nature.com/nnano/journal/v5/n3/abs/nnano.2010.6.html
Thursday, March 4, 2010
Junctionless transistor makes its debut
Site of the day: http://fooledbyrandomness.com/
Researchers in Ireland have succeeded in making the first junctionless transistor ever. The device, which resembles a structure first proposed way back in 1925 but not realized until now, has nearly "ideal" electrical properties, according to the team. It could potentially operate faster and use less power than any conventional transistor on the market today.
Transistors are the fundamental building blocks of modern electronic devices – and all existing transistors contain semiconductor junctions. The most common type of junction is the p–n junction, which is formed by the contact between a p-type piece of silicon – doped with impurities to create an excess of holes – and an n-type piece of silicon, doped to create an excess of electrons. Other junctions include the heterojunction, which is simply a p–n junction containing two different semiconductors, and the Schottky junction between metal and semiconductor.
The number of transistors on a single silicon microchip has been increasing exponentially since the early 1970s, and has gone up from a few hundred to over several billion today. As a result, transistors are becoming so tiny that it is becoming increasingly difficult to create high-quality junctions. In particular, it is very difficult to change the doping concentration of a material over distances shorter than about 10 nm. Junctionless transistors could therefore help chipmakers continue to make smaller and smaller devices.
Patented in 1925
Now, Jean-Pierre Colinge and colleagues at the Tyndall National Institute of University College Cork have dispensed with the very idea of a junction and instead have turned to a concept first proposed in 1925 by Austrian-Hungarian physicist Julius Edgar Lilienfield. Patented under the title "Device for controlling electric current", it is a simple resistor and contains a gate that controls the density of electrons and holes, and thus current flow.
The team's version of the device consists of a silicon nanowire in which current flow is perfectly controlled by a silicon gate that is separated from the nanowire by a thin insulating layer. The structure itself is very simple, looking a bit like a telephone cable that is fixed to a surface by a plastic clip (see figure). Crucially, there is no need to alter the doping over very short distances. Instead, the entire silicon nanowire is heavily n-doped, making it an excellent conductor. However, the gate is p-doped and its presence has the effect of depleting the number of electrons in the region of the nanowire under the gate.
If a voltage is simply applied along the nanowire, current cannot flow through this depleted region. According to Colinge, this region "squeezes" the current in the nanowire in the same way as the flow of water in a hose is stopped by squeezing it. However, if a voltage is applied to the gate, the squeezing effect is reduced and current can flow. The team also made a similar device with a p-type nanowire and n-type gate.
The most perfect of transistors
The structure is simple to build, even at the nanoscale, which means reduced costs compared with conventional junction fabrication technologies, which are becoming more and more complex. The device also has near-ideal electrical properties, adds Colinge, and behaves like the most perfect of transistors. This means that it hardly suffers at all from current leakage – the bane of conventional devices – and so could potentially operate faster and using less energy.
The Tyndall team says that it is now talking to some of the world's leading semiconductor companies to further develop and possibly license its technology.
"Although the idea of a transistor without junctions may seem quite unorthodox, the word "transistor" does not imply the presence of junctions, per se," write the researchers in Nature Nanotechnology, where the work was published. "A transistor is a solid-state device that controls current flow and the word transistor is a contraction of 'trans- resistor'."
(http://physicsworld.com/cws/article/news/41881)
Bloom Energy unveils fuel cell of the future
Site of the day: http://fooledbyrandomness.com/
A man stands next to a Bloom Energy server called a "Bloom Box" during a product launch at the eBay headquarters in San Jose, California. Bloom Energy, a Silicon Valley start up, introduced the "Bloom Box", a solid oxide fuel cell server that can generate electricity at a cost of 8 to 10 cents per kilowatt hour using natural gas.
Stealth start-up Bloom Energy on Wednesday publicly unveiled an innovative fuel cell that promises to deliver affordable, clean energy to even remote corners of the world.
Compact Bloom Servers built with energy cells made from silicon -- a plentiful element found in sand -- made their formal debut in an eBay building here partially powered by the energy source.
"Bloom fuel cell technology has the potential to revolutionize the energy industry," California governor Arnold Schwarzenegger said while introducing Bloom founder K.R. Sridhar.
"He is someone shaping the future of energy not just for California but for the world," Schwarzenegger said.
A high-powered audience gathered for the invitation-only event included Google co-founder Larry Page, eBay chief executive John Donahoe, and former US secretaries of state George Shultz and Colin Powell.
"The core of our technology simply is sand," Sridhar said pulling a black cloth off a clear glass container of sand and then holding up a greeting-card sized cell made from the material.
"It is available in plenty... and it has the scientific property that enabled us to make a fuel cell," he said.
Fuel cell technology dates back to the mid 1800s, but Bloom found a way to eliminate the need for expensive metals such as platinum and to generate electricity by pushing around oxygen molecules.
Bloom servers work with a variety of fuels, meaning users can freely switch to whatever is locally available or most affordable, according to Sridhar.
The servers, referred to by some as "Bloom boxes" despite Sridhar cringing at the nickname, have been secretly tested in California by a group of major corporations including eBay, Wal-Mart, and Coca Cola.
Google was Bloom's first customer, buying four servers that it installed at its campus in Mountain View, California.
"I'm a big supporter of this," Page said during an on-stage chat with renowned Silicon Valley venture capitalist John Doerr of Kleiner Perkins Caulfield & Byers, a major backer of Bloom.
"I'd love to see us have a whole data center running on this at some point when they are ready," Page said.
Bloom servers capable of pumping out 100 kilowatts of electricity each cost 700,000 to 800,000 dollars but the price is expected to plummet as production ramps up and efficiencies of scale are achieved.
Sridhar predicted it will take about a decade for the technology to get to the point where it can be used in homes.
Bloom servers are 60 percent cleaner than coal-fired power plants and produce reliable energy on-site instead of having electricity routed through wires from far-off generation plants, Schwarzenegger said.
The inspiration for the fuel cell is rooted in Sridhar's decade as a university professor working on ways to sustain a human colony on Mars.
"I was trying to make Mars our second home," Sridhar said. "The technology was robust but, unfortunately, I couldn't say the same thing about the funding and the rockets."
Sridhar focused his inventive energy on Earth's need to curb pollution and sate growing energy demands. "If we continued the way we were going we would be handing our children a broken planet," he said.
The cells are described as being twice as efficient as the US electricity grid, meaning it takes half the fuel to produce the same amount of energy.
Sridhar hefted a brick-sized fuel cell in one hand, saying it could power a standard light bulb but will soon be able to satisfy the electricity needs of a typical US home.
"In a few years we will use it to make a home energy server of the future," Sridhar said.
Sridhar pulled back a curtain to reveal a set of Bloom Servers -- refrigerator-sized metal boxes housing stacks of fuel cells.
"That's my baby," he said. "Isn't she beautiful."
Electricity generated by Bloom servers costs about nine cents per kilowatt/hour as opposed to the 14 or 15 cents typically charged here by utilities.
The cost of the servers is recovered in three to five years by energy savings, according to Sridhar. The servers are guaranteed for 10 years. Sridhar would not disclose the lifespans of the fuel cells.
"We sent our chief financial officer to make sure this thing penciled out," Donahoe said of eBay's decision to try Bloom technology. "It is something that makes good green sense making good business sense."
Former secretary of state Colin Powell, a Bloom board member and retired general, said the servers could be a boon to the military, which has grown increasingly energy-dependent as technology infuses the tools of war.
"This is a breakthrough," Powell said. "Sooner or later it is going to be in homes all across America. Think what it will ultimately do for humankind."
(http://www.physorg.com/news186246027.html)
Other articles:
http://www.physorg.com/news186123245.html
http://www.technologyreview.com/energy/24650/
A man stands next to a Bloom Energy server called a "Bloom Box" during a product launch at the eBay headquarters in San Jose, California. Bloom Energy, a Silicon Valley start up, introduced the "Bloom Box", a solid oxide fuel cell server that can generate electricity at a cost of 8 to 10 cents per kilowatt hour using natural gas.
Stealth start-up Bloom Energy on Wednesday publicly unveiled an innovative fuel cell that promises to deliver affordable, clean energy to even remote corners of the world.
Compact Bloom Servers built with energy cells made from silicon -- a plentiful element found in sand -- made their formal debut in an eBay building here partially powered by the energy source.
"Bloom fuel cell technology has the potential to revolutionize the energy industry," California governor Arnold Schwarzenegger said while introducing Bloom founder K.R. Sridhar.
"He is someone shaping the future of energy not just for California but for the world," Schwarzenegger said.
A high-powered audience gathered for the invitation-only event included Google co-founder Larry Page, eBay chief executive John Donahoe, and former US secretaries of state George Shultz and Colin Powell.
"The core of our technology simply is sand," Sridhar said pulling a black cloth off a clear glass container of sand and then holding up a greeting-card sized cell made from the material.
"It is available in plenty... and it has the scientific property that enabled us to make a fuel cell," he said.
Fuel cell technology dates back to the mid 1800s, but Bloom found a way to eliminate the need for expensive metals such as platinum and to generate electricity by pushing around oxygen molecules.
Bloom servers work with a variety of fuels, meaning users can freely switch to whatever is locally available or most affordable, according to Sridhar.
The servers, referred to by some as "Bloom boxes" despite Sridhar cringing at the nickname, have been secretly tested in California by a group of major corporations including eBay, Wal-Mart, and Coca Cola.
Google was Bloom's first customer, buying four servers that it installed at its campus in Mountain View, California.
"I'm a big supporter of this," Page said during an on-stage chat with renowned Silicon Valley venture capitalist John Doerr of Kleiner Perkins Caulfield & Byers, a major backer of Bloom.
"I'd love to see us have a whole data center running on this at some point when they are ready," Page said.
Bloom servers capable of pumping out 100 kilowatts of electricity each cost 700,000 to 800,000 dollars but the price is expected to plummet as production ramps up and efficiencies of scale are achieved.
Sridhar predicted it will take about a decade for the technology to get to the point where it can be used in homes.
Bloom servers are 60 percent cleaner than coal-fired power plants and produce reliable energy on-site instead of having electricity routed through wires from far-off generation plants, Schwarzenegger said.
The inspiration for the fuel cell is rooted in Sridhar's decade as a university professor working on ways to sustain a human colony on Mars.
"I was trying to make Mars our second home," Sridhar said. "The technology was robust but, unfortunately, I couldn't say the same thing about the funding and the rockets."
Sridhar focused his inventive energy on Earth's need to curb pollution and sate growing energy demands. "If we continued the way we were going we would be handing our children a broken planet," he said.
The cells are described as being twice as efficient as the US electricity grid, meaning it takes half the fuel to produce the same amount of energy.
Sridhar hefted a brick-sized fuel cell in one hand, saying it could power a standard light bulb but will soon be able to satisfy the electricity needs of a typical US home.
"In a few years we will use it to make a home energy server of the future," Sridhar said.
Sridhar pulled back a curtain to reveal a set of Bloom Servers -- refrigerator-sized metal boxes housing stacks of fuel cells.
"That's my baby," he said. "Isn't she beautiful."
Electricity generated by Bloom servers costs about nine cents per kilowatt/hour as opposed to the 14 or 15 cents typically charged here by utilities.
The cost of the servers is recovered in three to five years by energy savings, according to Sridhar. The servers are guaranteed for 10 years. Sridhar would not disclose the lifespans of the fuel cells.
"We sent our chief financial officer to make sure this thing penciled out," Donahoe said of eBay's decision to try Bloom technology. "It is something that makes good green sense making good business sense."
Former secretary of state Colin Powell, a Bloom board member and retired general, said the servers could be a boon to the military, which has grown increasingly energy-dependent as technology infuses the tools of war.
"This is a breakthrough," Powell said. "Sooner or later it is going to be in homes all across America. Think what it will ultimately do for humankind."
(http://www.physorg.com/news186246027.html)
Other articles:
http://www.physorg.com/news186123245.html
http://www.technologyreview.com/energy/24650/
Energy-Efficient Lighting Made Without Mercury
Site of the day: http://fooledbyrandomness.com/
ScienceDaily (Feb. 15, 2010) — RTI International has developed a revolutionary lighting technology that is more energy efficient than the common incandescent light bulb and does not contain mercury, making it environmentally safer than the compact fluorescent light (CFL) bulb.
At the core of RTI's breakthrough is an advanced nanofiber structure that provides exceptional lighting management. Nanofibers are materials with diameters and surface features much smaller than the human hair but with comparable lengths.
RTI's technology, which was funded in part by the Department of Energy's Solid-State Lighting program, centers around advancements in the nanoscale properties of materials to create high-performance, nanofiber-based reflectors and photoluminescent nanofibers (PLN). When the two nanoscale technologies are combined, a high-efficiency lighting device is produced that is capable of generating in excess of 55 lumens of light output per electrical watt consumed. This efficiency is more than five times greater than that of traditional incandescent bulbs.
"By using flexible photoluminescent nanofiber technologies for light management, RTI has opened the door to the creation of new designs for solid-state lighting applications," says Lynn Davis, Ph.D., director of RTI's Nanoscale Materials Program. "This new class of materials can provide cost-effective, safe and efficient lighting solutions."
Additionally, RTI's technology produces an aesthetically pleasing light with better color rendering properties than is typically found in CFLs. The technology has demonstrated color rendering indices in excess of 90 for warm white, neutral white, and cool white illumination sources.
"Because lighting consumes almost one-fourth of all electricity generated in the United States, our technology could have a significant impact in reducing energy consumption and carbon dioxide emissions," Davis said. "The technology also does not contain mercury, which makes it more environmentally friendly and safer to handle than CFLs and other fluorescent lamps."
RTI is continuing development of this technology and is actively pursuing commercialization opportunities in the marketplace. It is anticipated that commercial products containing this breakthrough will be available in three to five years.
(http://www.sciencedaily.com/releases/2010/02/100211140629.htm)
ScienceDaily (Feb. 15, 2010) — RTI International has developed a revolutionary lighting technology that is more energy efficient than the common incandescent light bulb and does not contain mercury, making it environmentally safer than the compact fluorescent light (CFL) bulb.
At the core of RTI's breakthrough is an advanced nanofiber structure that provides exceptional lighting management. Nanofibers are materials with diameters and surface features much smaller than the human hair but with comparable lengths.
RTI's technology, which was funded in part by the Department of Energy's Solid-State Lighting program, centers around advancements in the nanoscale properties of materials to create high-performance, nanofiber-based reflectors and photoluminescent nanofibers (PLN). When the two nanoscale technologies are combined, a high-efficiency lighting device is produced that is capable of generating in excess of 55 lumens of light output per electrical watt consumed. This efficiency is more than five times greater than that of traditional incandescent bulbs.
"By using flexible photoluminescent nanofiber technologies for light management, RTI has opened the door to the creation of new designs for solid-state lighting applications," says Lynn Davis, Ph.D., director of RTI's Nanoscale Materials Program. "This new class of materials can provide cost-effective, safe and efficient lighting solutions."
Additionally, RTI's technology produces an aesthetically pleasing light with better color rendering properties than is typically found in CFLs. The technology has demonstrated color rendering indices in excess of 90 for warm white, neutral white, and cool white illumination sources.
"Because lighting consumes almost one-fourth of all electricity generated in the United States, our technology could have a significant impact in reducing energy consumption and carbon dioxide emissions," Davis said. "The technology also does not contain mercury, which makes it more environmentally friendly and safer to handle than CFLs and other fluorescent lamps."
RTI is continuing development of this technology and is actively pursuing commercialization opportunities in the marketplace. It is anticipated that commercial products containing this breakthrough will be available in three to five years.
(http://www.sciencedaily.com/releases/2010/02/100211140629.htm)
New Energy Source from the Common Pea: Scientists Create a Solar Energy Device from a Plant Protein Structure
Site of the day: http://fooledbyrandomness.com/
ScienceDaily (Mar. 4, 2010) — If harnessing the unlimited solar power of the sun were easy, we wouldn't still have the greenhouse gas problem that results from the use of fossil fuel. And while solar energy systems work moderately well in hot desert climates, they are still inefficient and contribute only a small percentage of the general energy demand. A new solution may be coming from an unexpected source -- a source that may be on your dinner plate tonight.
"Looking at the most complicated membrane structure found in a plant, we deciphered a complex membrane protein structure which is the core of our new proposed model for developing 'green' energy," says structural biologist Prof. Nathan Nelson of Tel Aviv University's Department of Biochemistry. Isolating the minute crystals of the PSI super complex from the pea plant, Prof. Nelson suggests these crystals can be illuminated and used as small battery chargers or form the core of more efficient artificial solar cells.
Nanoscience is the science of small particles of materials and is one of the most important research frontiers in modern technology. In nature, positioning of molecules with sub-nanometer precision is routine, and crucial to the operation of biological complexes such as photosynthetic complexes. Prof. Nelson's research concentrates on this aspect.
The mighty PSI
To generate useful energy, plants have evolved very sophisticated "nano-machinery" which operates with light as its energy source and gives a perfect quantum yield of 100%. Called the Photosystem I (PSI) complex, this complex was isolated from pea leaves, crystalized and its crystal structure determined by Prof. Nelson to high resolution, which enabled him to describe in detail its intricate structure.
"My research aims to come close to achieving the energy production that plants can obtain when converting sun to sugars in their green leaves," explains Prof. Nelson.
Described in 1905 by Albert Einstein, quantum physics and photons explained the basic principles of how light energy works. Once light is absorbed in plant leaves, it energizes an electron which is subsequently used to support a biochemical reaction, like sugar production.
"If we could come even close to how plants are manufacturing their sugar energy, we'd have a breakthrough. It's therefore important to solve the structure of this nano-machine to understand its function," says Prof. Nelson, whose lab is laying the foundations for this possibility.
Since the PSI reaction center is a pigment-protein complex responsible for the photosynthetic conversion of light energy to another form of energy like chemical energy, these reaction centers, thousands of which are precisely packed in the crystals, may be used to convert light energy to electricity and serve as electronic components in a variety of different devices.
"One can imagine our amazement and joy when, upon illumination of those crystals placed on gold covered plates, we were able to generate a voltage of 10 volts. This won't solve our world's energy problem, but this could be assembled in power switches for low-power solar needs, for example," he concludes.
(http://www.sciencedaily.com/releases/2010/03/100304112237.htm)
ScienceDaily (Mar. 4, 2010) — If harnessing the unlimited solar power of the sun were easy, we wouldn't still have the greenhouse gas problem that results from the use of fossil fuel. And while solar energy systems work moderately well in hot desert climates, they are still inefficient and contribute only a small percentage of the general energy demand. A new solution may be coming from an unexpected source -- a source that may be on your dinner plate tonight.
"Looking at the most complicated membrane structure found in a plant, we deciphered a complex membrane protein structure which is the core of our new proposed model for developing 'green' energy," says structural biologist Prof. Nathan Nelson of Tel Aviv University's Department of Biochemistry. Isolating the minute crystals of the PSI super complex from the pea plant, Prof. Nelson suggests these crystals can be illuminated and used as small battery chargers or form the core of more efficient artificial solar cells.
Nanoscience is the science of small particles of materials and is one of the most important research frontiers in modern technology. In nature, positioning of molecules with sub-nanometer precision is routine, and crucial to the operation of biological complexes such as photosynthetic complexes. Prof. Nelson's research concentrates on this aspect.
The mighty PSI
To generate useful energy, plants have evolved very sophisticated "nano-machinery" which operates with light as its energy source and gives a perfect quantum yield of 100%. Called the Photosystem I (PSI) complex, this complex was isolated from pea leaves, crystalized and its crystal structure determined by Prof. Nelson to high resolution, which enabled him to describe in detail its intricate structure.
"My research aims to come close to achieving the energy production that plants can obtain when converting sun to sugars in their green leaves," explains Prof. Nelson.
Described in 1905 by Albert Einstein, quantum physics and photons explained the basic principles of how light energy works. Once light is absorbed in plant leaves, it energizes an electron which is subsequently used to support a biochemical reaction, like sugar production.
"If we could come even close to how plants are manufacturing their sugar energy, we'd have a breakthrough. It's therefore important to solve the structure of this nano-machine to understand its function," says Prof. Nelson, whose lab is laying the foundations for this possibility.
Since the PSI reaction center is a pigment-protein complex responsible for the photosynthetic conversion of light energy to another form of energy like chemical energy, these reaction centers, thousands of which are precisely packed in the crystals, may be used to convert light energy to electricity and serve as electronic components in a variety of different devices.
"One can imagine our amazement and joy when, upon illumination of those crystals placed on gold covered plates, we were able to generate a voltage of 10 volts. This won't solve our world's energy problem, but this could be assembled in power switches for low-power solar needs, for example," he concludes.
(http://www.sciencedaily.com/releases/2010/03/100304112237.htm)
Saturday, February 27, 2010
Wireless Power Transmission
Site of the day: http://www.wired.com/
Invisible Power
Marin Soljacic couldn't sleep. The problem was his wife's Nokia cell phone. The tyrannical device beeped on the bedside table when it needed to be plugged in. It could not be disabled.
Instead of taking a hammer to the phone, Soljacic marveled at the fact that this device, and billions of others like it, was sitting a few feet away from all the electricity it could ever need. Why couldn't it receive power wirelessly, just as laptops get Wi-Fi?
Being a physics professor, not an electrical engineer, Soljacic didn't know the history of failed attempts to produce wireless electricity. (Thomas Edison and his rival Nikola Tesla were among the first to envision long-distance power-beaming.) Soljacic also didn't pause to consider conduction, the kind of close-range charging used in electric toothbrushes, which is about as far as wireless electricity got before him.
Soljacic learned that if you could get two magnetic fields to resonate -- to sing the same note, in effect -- they could transfer an electric current. With two large magnetic coils, he found in an experiment described in Science magazine in 2007, you can throw 60 watts across a room, powering a lightbulb. (Keeping the two resonators in perfect harmony over a distance is not simple; Soljacic spent several years running lab experiments before he built a system that worked reliably.)
MIT, his employer, quickly patented the technology (Soljacic's name is on the patent) and encouraged Soljacic to start a company. He would sit on the board but find executives to run it full time. The result can be found on the second floor of a brick building in Cambridge, Mass. leased to the company by the big-and-tall tailor on the ground level.
WiTricity's 15 employees are hard at work proving that Soljacic's magnetic coils can power almost any electrical device. David Schatz, director of business development, shows me a TV, a DVD player and a computer, all of them wireless.
"This was our No. 1 request from business users," Schatz says, switching on a projector. "Look: no batteries, no wires, nothing up my sleeve." The coil sending out the power is hidden behind an abstract painting that the CEO's wife rescued from their basement.
Schatz is the first to admit that the housing they've hurriedly built for the receiving coils is too bulky. "No one would want to buy this," he says, pointing to the pack that juts out from the back of the laptop, a pregnant plastic bulge that's about a third as large as the device itself.
Given sufficient cooperation from equipment manufacturers, WiTricity is confident that it can incorporate its coil into the guts of any device. (Think of how computermakers like Apple (AAPL, Fortune 500) turned bulky Webcams into fingernail-size lenses that fit in a thin laptop case.) CEO Eric Giler, a veteran tech executive who ran a telecom company for 22 years, understands the importance of letting potential partners play with patented technology.
So far about a dozen companies -- including Intel (INTC, Fortune 500) and Sony (SNE) -- have tried replicating Soljacic's groundbreaking MIT experiment in their own research facilities, just to make sure it's the real deal. That might make other CEOs nervous, but not Giler.
"Our best customers are going to be the guys who try to do this," he says, "because it is really hard." The company is also talking to furniture manufacturers about fitting coils into desks and cubicle walls. The first announcement of a WiTricity partner product is expected toward the end of 2010.
Most of Giler's potential customers have one major question: safety. "There's a real perceptual problem," he says. "People think we're putting electricity in the air, and that's called lightning, and they know to stay away from that."
In fact, the coils turn electricity into magnetic fields, then back into electricity. And as any physicist will tell you, magnetic fields interact weakly with humans; as far as the fields are concerned, we are no different from air. (The Earth itself exudes a magnetic field.)
Initially, Giler was skeptical. Magnetism from MRI machines can disable pacemakers. Wouldn't wireless electricity pose similar risks? Soljacic replied that MRI magnetism is about 10,000 times stronger than his version. The Institute of Physics in London concurs: WiTricity's magnetic field "has no detrimental effects on the human body."
Giler makes a point of standing between the coils whenever he demonstrates the technology. At the Nikkei electronics conference in Tokyo in October, he was able to power a 1,000-watt klieg light from across the room -- a far cry from that 60-watt lightbulb in Soljacic's first experiment. "We're going up the power curve," he says.
WiTricity's record so far is 3,000 watts -- enough to fully charge an electric car, so long as it's in the same room (or garage). How big could WiTricity get? "Every single person in the world can relate to the problem of running out of batteries or having wires everywhere," Giler says. "The market is so potentially huge that numbers become meaningless."
A wireless electric world could free up designers to create entirely new kinds of products, no longer hemmed in by the need for boxy batteries or power supplies. As one of Giler's VC investors says, "I bet you that's your bestseller in five years' time. You don't even know what it is yet."
By Chris Taylor
More articles:
http://gizmodo.com/5471431/mit-wireless-power-discovery-proves-two-is-better-than-one
http://www.newscientist.com/article/dn18521-more-is-merrier-for-wireless-power-supply.html
Thursday, February 25, 2010
Nanoprinter could have cells lining up to be tested
Site of the day: http://openwetware.org/
BORROWING a trick from the office photocopier may make it possible for a nanoscale printer to precisely manipulate biological cells for use in artificial tissue.
In 2007, John Rogers at the University of Illinois at Urbana-Champaign and colleagues produced a printer small enough to print electronic circuits from conductive ink on the nanoscale. By modifying the technique, they think it should be possible to manipulate biological cells or biomolecules such as DNA, says Rogers.
The team's electrohydrodynamic jet (e-jet) printer works by establishing a voltage difference between its metallic nozzle and a substrate below. The resulting electric fields cause charged ions in the ink to congregate in a meniscus at the nozzle. Because the charged ions repel one another, the meniscus deforms into the shape of a cone, creating an ultra-fine tip from which tiny ink droplets are shed.
This process produces an imbalance in the quantities of positive and negative ions in the printed ink, and the team realised that by switching the polarity of the voltage, they could print intricate patterns of positive or negative charge onto the substrate (Nano Letters, DOI: 10.1021/nl903495f).
Once a pattern of charge is printed onto a substrate, the static could attract charged molecules and cells, marshalling them into shape in the same way toner inside a photocopier is forced into the required design. "[But] xerography itself does not offer comparable resolution," says Rogers.
The technique could complement cell-printing techniques for artificial tissue manufacture by helping to guide cells too fragile to be printed into position inside a 3D matrix. "It could be very useful indirect manipulation of cells," says Vladimir Mironov, a biofabrication researcher at the Medical University of South Carolina in Charleston.
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