Working as a Team, Bacteria Spin Gears
by HENRY FOUNTAIN for New York Times
One bacterium, working alone, can’t accomplish much. But put a bunch of them together, and they can move mountains.Well, maybe not mountains. But how about a tiny gear? Researchers at Argonne National Laboratory, Northwestern and Princeton have shown that the collective swimming behavior of bacteria can be harnessed for work. While the process is not very efficient, it is a promising step toward the development of hybrid biological and micromechanical machines.In some respects, bacterial swimming resembles Brownian motion, the random movement of particles or molecules in a medium. But Igor S. Aranson, an Argonne researcher who is the senior author of a paper describing the work in The Proceedings of the National Academy of Sciences, said that in equilibrium conditions, it was impossible to extract useful energy from Brownian motion — the laws of thermodynamics did not allow it.“But bacteria, they don’t know about this law,” Dr. Aranson said. The researchers used tiny polymer gears with asymmetric teeth floating in a thin film teeming with Bacillus subtilis, a bacterial species known for its swimming ability. Above a concentration of about 10 billion bacteria per cubic centimeter, the gear would rotate. Dr. Aranson said that unlike molecules in Brownian motion, which reflect off whatever they strike, when the bacteria hit a tooth, “they just keep pushing.” They slide along the edge of the tooth until they reach the “V” junction where the next tooth starts. Since one edge of each tooth is longer than the other, more bacteria slide along the long edges, transferring more momentum to them and rotating the gear in one direction.One of the limitations of the process, Dr. Aranson said, is that the bacteria eventually run out of nutrients. But they can stop pushing even before that. “Bacteria behave too much like people,” he said. “They start to do something else.”
Printable Batteries
By CLAY RISEN for New York Times
Though you may not be aware of it, the technology already exists to create a video screen thin enough -- and flexible enough -- to fit seamlessly into the pages of this magazine. Ultrathin electronic devices can be built using a special inkjet printer that squirts fine layers of complex compounds instead of ink. When the compounds dry, they leave behind sheer metallic films, which in the right combination could act as thermometers, light sensors, even computer chips. So why haven't you seen these gadgets yet? In part because they are hard to power: even the smallest lithium-ion watch battery is too bulky.The solution is to print batteries too. This year, a research team at the Fraunhofer Research Institution for Electronic Nano Systems revealed a 0.6-millimeter-thick battery. It consists of a stack of metal pastes that act as anode, cathode and electrolyte, bound on top and bottom by carbon layers that collect electricity and deliver it to the attached device. This product can be built right into the device it's powering, as part of the production process, so there's no need for an additional assembly line. And the battery can be made as large or as small as needed, simply by printing more of it. The list of possible applications is endless -- from bandages that release medication when they sense an increase in body temperature to wallpaper that changes color at the flick of a switch.We're not talking megawatts, of course. According to Andreas Willert, one of the researchers, it takes about 15 square centimeters of printable battery to provide the same power as a single watch battery. But 15 square centimeters could be enough to power, say, a blinking magazine cover for a month. The Fraunhofer Research Institution introduced its battery at a nanotech expo in Japan in February. The next step is to open a small production line, which Willert expects will be ready next year. Which means that soon, instead of reading these pages, you might be watching them.
What is Nanotechnology
Nanotechnology, shortened to “nanotech”, is the study of the controlling of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller in at least one dimension, and involves developing materials or devices within that size. Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale. There has been much debate on the future implications of nanotechnology. Nanotechnology has the potential to create many new materials and devices with a vast range of applications, such as in medicine, electronics and energy production. On the other hand, nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nanomaterials,[1] and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.
by HENRY FOUNTAIN for New York Times
One bacterium, working alone, can’t accomplish much. But put a bunch of them together, and they can move mountains.Well, maybe not mountains. But how about a tiny gear? Researchers at Argonne National Laboratory, Northwestern and Princeton have shown that the collective swimming behavior of bacteria can be harnessed for work. While the process is not very efficient, it is a promising step toward the development of hybrid biological and micromechanical machines.In some respects, bacterial swimming resembles Brownian motion, the random movement of particles or molecules in a medium. But Igor S. Aranson, an Argonne researcher who is the senior author of a paper describing the work in The Proceedings of the National Academy of Sciences, said that in equilibrium conditions, it was impossible to extract useful energy from Brownian motion — the laws of thermodynamics did not allow it.“But bacteria, they don’t know about this law,” Dr. Aranson said. The researchers used tiny polymer gears with asymmetric teeth floating in a thin film teeming with Bacillus subtilis, a bacterial species known for its swimming ability. Above a concentration of about 10 billion bacteria per cubic centimeter, the gear would rotate. Dr. Aranson said that unlike molecules in Brownian motion, which reflect off whatever they strike, when the bacteria hit a tooth, “they just keep pushing.” They slide along the edge of the tooth until they reach the “V” junction where the next tooth starts. Since one edge of each tooth is longer than the other, more bacteria slide along the long edges, transferring more momentum to them and rotating the gear in one direction.One of the limitations of the process, Dr. Aranson said, is that the bacteria eventually run out of nutrients. But they can stop pushing even before that. “Bacteria behave too much like people,” he said. “They start to do something else.”
Printable Batteries
By CLAY RISEN for New York Times
Though you may not be aware of it, the technology already exists to create a video screen thin enough -- and flexible enough -- to fit seamlessly into the pages of this magazine. Ultrathin electronic devices can be built using a special inkjet printer that squirts fine layers of complex compounds instead of ink. When the compounds dry, they leave behind sheer metallic films, which in the right combination could act as thermometers, light sensors, even computer chips. So why haven't you seen these gadgets yet? In part because they are hard to power: even the smallest lithium-ion watch battery is too bulky.The solution is to print batteries too. This year, a research team at the Fraunhofer Research Institution for Electronic Nano Systems revealed a 0.6-millimeter-thick battery. It consists of a stack of metal pastes that act as anode, cathode and electrolyte, bound on top and bottom by carbon layers that collect electricity and deliver it to the attached device. This product can be built right into the device it's powering, as part of the production process, so there's no need for an additional assembly line. And the battery can be made as large or as small as needed, simply by printing more of it. The list of possible applications is endless -- from bandages that release medication when they sense an increase in body temperature to wallpaper that changes color at the flick of a switch.We're not talking megawatts, of course. According to Andreas Willert, one of the researchers, it takes about 15 square centimeters of printable battery to provide the same power as a single watch battery. But 15 square centimeters could be enough to power, say, a blinking magazine cover for a month. The Fraunhofer Research Institution introduced its battery at a nanotech expo in Japan in February. The next step is to open a small production line, which Willert expects will be ready next year. Which means that soon, instead of reading these pages, you might be watching them.
What is Nanotechnology
Nanotechnology, shortened to “nanotech”, is the study of the controlling of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller in at least one dimension, and involves developing materials or devices within that size. Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale. There has been much debate on the future implications of nanotechnology. Nanotechnology has the potential to create many new materials and devices with a vast range of applications, such as in medicine, electronics and energy production. On the other hand, nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nanomaterials,[1] and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.