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Researchers build tiny batteries with viruses

MIT scientists have harnessed the construction talents of tiny viruses to build ultra-small "nanowire" structures for use in very thin lithium-ion batteries.

By manipulating a few genes inside these viruses, the team was able to coax the organisms to grow and self-assemble into a functional electronic device.

The goal of the work, led by MIT Professors Angela Belcher, Paula Hammond and Yet-Ming Chiang, is to create batteries that cram as much electrical energy into as small or lightweight a package as possible. The batteries they hope to build could range from the size of a grain of rice up to the size of existing hearing aid batteries.

Batteries consist of two opposite electrodes -- an anode and cathode -- separated by an electrolyte. In the current work, the MIT team used an intricate assembly process to create the anode.

Specifically, they manipulated the genes in a laboratory strain of a common virus, making the microbes collect exotic materials -- cobalt oxide and gold. And because these viruses are negatively charged, they can be layered between oppositely charged polymers to form thin, flexible sheets.

The result? A dense, virus-loaded film that serves as an anode.

A report on the work will appear in the April 7 issue of Science.

In their research, the MIT team altered the virus's genes so they make protein coats that collect molecules of cobalt oxide, plus gold. The viruses then align themselves on the polymer surface to form ultrathin wires. Each virus, and thus the wire, is only 6 nanometers (6 billionths of a meter) in diameter, and 880 nanometers in length.

"We can make them in larger diameters," Belcher said, "but they are all 880 nanometers in length," which matches the length of the individual virus particles. And, "once we've altered the genes of the virus to grow the electrode material, we can easily clone millions of identical copies of the virus to use in assembling our batteries.

"For the metal oxide we chose cobalt oxide because it has very good specific capacity, which will produce batteries with high energy density," meaning it can store two or three times more energy for its size and weight compared to previously used battery electrode materials. And adding the gold further increased the wires' energy density, she added.

Equally important, the reactions needed to create nanowires occur at normal room temperatures and pressures, so there is no need for expensive pressure-cooking technology to get the job done... virus battery

Carbon Nanotubes with a Memory

Carbon nanotubes have successfully been made into a variety of nanoscale circuit components, including transistors, inverters, and switches. Now, a pair of scientists has made a rough, yet promising, flash memory device out of carbon nanotubes. The device is a long way from a finished, marketable product, but it nonetheless represents a significant step in the drive to incorporate carbon nanotubes into mainstream electronics.

“Unlike similar devices that have been made, which use carbon nanotubes but can only operate at very low, very impractical temperatures, our device displays impressive long-term information retention characteristics at room temperature,” said lead researcher Jiyan Dai, a physicist at The Hong Kong Polytechnic University, to PhysOrg.com. “This indicates that mainstream carbon nanotube-based flash memory devices are a real possibility.”

Flash memory devices are currently used to store data in many types of electronic items, including digital cameras, USB memory sticks, and cell phones. Flash memory is considered a “non-volatile” form of memory, meaning it can retain data without a constant supply of power.

A typical flash memory device stores information within a grid of transistors called cells. Each cell consists of three layers: a “control gate” compound and a “floating gate” compound separated by a thin layer of an insulating oxide compound. When a voltage is applied to the cell, electrons build up as negative electric charge in the floating gate. At a certain threshold of charge, the floating gate is considered closed and the cell is thought to have a value of “0.” When the charge drops below that level, the gate is open and the cell has a value of “1.” In this way, each cell is able to hold one bit of information (there are eight bits in one byte).

Dai and co-researcher X.B. Lu created their flash memory device using carbon nanotubes as the charge-storage layer. As described in a paper in the online edition of Applied Physics Letters, they embedded the nanotubes in a compound made of the elements hafnium, aluminum, and oxygen, abbreviated HfAlO, which serves as both the control gate and the oxide layer. This carbon-nanotube “sandwich,” with each layer only several nanometers in thickness, sits on a substrate of silicon.

via http://www.physorg.com/news63291916.html

Nano-welding could join molecular devices

A nanoscale welding technique has been developed by sparking high-temperature chemical reactions inside "nanopores".

The technique could ultimately be used to weld together nanoscale components and could also lend itself to nanoscopic chemistry experiments, say the researchers.

By lacing a micrometre-thick film of aluminium with nanoscopic holes and filling the holes with iron oxide, the researchers produced a high-temperature "thermite" reaction.

This reaction is used every day in welding and fireworks, and as a simple but spectacular classroom chemistry demonstration. Thermite reactions are normally produced by heating a mixture of aluminium and iron oxide powders, and produce fiery sparks and molten iron.

Etching nanopores

"Instead of just making a wire or a tube like lots of nanotechnology projects, we wanted to actually try and do some chemistry," says Christiaan Richter of Northeastern University in Boston, US, who presented his research at the National Meeting of the American Chemical Society in Atlanta this week.

Richter and colleagues used electrochemical acid etching to create "nanopores" 20 nanometres wide in the surface of aluminium film, at a density of more than a billion per square centimetre.

The pores were made by placing the aluminium film in a solution of weak acid with an electric current running through it. At first, random dimples appear in the aluminium's surface, but if the right current is applied for long enough nanopores form in a regular hexagonal arrangement. This happens due to small differences in electric potential across the surface of the film, which affect the acid solution.

Using a similar electrochemical trick the researchers then filled the nanopores with iron oxide, triggering a reaction that produced temperatures up to 4000°C. nano welding

Using a microwave for synthesis of nanomaterials

Virginia Commonwealth University chemists, using a simple, commercial microwave oven, have developed a new method for the synthesis of nanomaterials that can control the dimensions and properties of rods and wires that are just one billionth of a meter in size.

The method, known as microwave irradiation, or MWI, is considered a fast and easy way to create highly versatile, tailored nanorods and nanowires to be used in medical applications, drug delivery, sensors, communications and optical devices because microwave heating can provide significant enhancement in reaction rates.

M. Samy El-Shall, Ph.D., professor of chemistry and affiliate professor of chemical engineering at VCU, is discussing his ongoing work of the design, synthesis and characterization of nanoparticles at the American Chemical Society National Meeting & Exposition in Atlanta, March 26-30. In addition, his colleague, Asit Baran Panda, a post-doctoral fellow in the VCU Department of Chemistry, will present this study.

“The synthesis of new materials made of particles, rods and wires with dimensions in the nanometer scale is among the most active areas of research in science due to the unique properties of these materials compared to conventional materials made from micron sized particles,” said El-Shall, who is lead author of the study.

“MWI is unique in providing scaled-up processes thus leading to a potentially important industrial advancement in the large-scale synthesis of nanomaterials,” said El-Shall...

news release

Cerium oxide nanotubes get noticed

Chemists and materials scientists often study "nanotubes" -- capsule-shaped molecules only a few billionths of a meter in width. In nanotube form, many materials take on useful, unique properties, such as physical strength and excellent conductivity. Carbon nanotubes are the most widely investigated variety. Now, in pioneering research, scientists at the U.S. DoE's Brookhaven National Laboratory have created and investigated the properties of nanotubes made of a different, yet equally interesting material: cerium oxide.

"Cerium oxide nanotubes have potential applications as catalysts in vehicle emission-control systems and even fuel cells," says Brookhaven chemist Wei-Qiang Han, the lead scientist involved in the work. "But until very recently, they haven't been studied."

Han and his colleagues are in the midst of ongoing research into the structure and properties of cerium oxide nanotubes. As part of this, they have devised a method to synthesize cerium oxide nanotubes of high quality. First, they allow the compounds cerium nitrate and ammonia hydroxide to chemically react. Initially, this reaction forms "one-dimensional" nanostructures, such as rods and sheets, made of the intermediate product cerium hydroxide. The intermediate product is then quickly cooled to zero degrees Celsius, which freezes those structures into place. By letting the chemical reaction proceed over a long period of time, a process called "aging," the hydrogen is eventually removed from the intermediate product and a large quantity of the desired end product -- cerium oxide nanotubes -- is formed... cerium oxide nanotubes

Center For Responsible Nanotechnology Engages Leading Experts To Discuss Nanotech's Impact

The Center for Responsible Nanotechnology (CRN) today announced its first series of new research papers in which industry experts predict profound impacts of nanotechnology on society. Eleven original essays by members of CRN's Global Task Force appear in the latest issue of the journal Nanotechnology Perceptions, published today. From military and security issues to human enhancement, artificial intelligence, and more, these papers give readers a peek under the lid of Pandora's box to see what the future might hold.

Ray Kurzweil, renowned inventor, entrepreneur, and best-selling author, explained, "As the pace of technological advancement rapidly accelerates, it becomes increasingly important to promote knowledgeable and insightful discussion of both promise and peril. I'm very pleased to take part in this effort by including my own essay, and by hosting discussion of these essays on the 'MindX' discussion board at KurzweilAI.net."

Nanotechnology Perceptions is a peer-reviewed academic journal of the Collegium Basilea in Basel, Switzerland. "We jumped at the chance to publish the CRN Task Force essays," said Jeremy Ramsden, editor-in-chief of the journal. "To us, these papers represent world-class thinking about some of the most important challenges that human society will ever face."

In August 2005, the Center for Responsible Nanotechnology, a non-profit research and advocacy organization, formed its Global Task Force to study the societal implications of molecular manufacturing, an advanced form of nanotechnology. Bringing together a diverse group of world-class experts from multiple disciplines, CRN is spearheading an historic, collaborative effort to develop comprehensive recommendations for the safe and responsible use of this rapidly emerging technology... read

New 3D Magnetic Tweezers

Professor Gwo-Bin Vincent Lee, from National Cheng Kung University, Taiwan, and his colleagues have manufactured three-dimensional, micromachined magnetic tweezers to manipulate DNA molecules. Their method was published in the February 7, 2006 issue of Nanotechnology.

"This study could provide a provide a powerful tool for exploring the bio-physical properties of biomolecules, bio-polymers and cells," Lee said.

Lee's team made magnetic tweezers from six, hexagonal micro-electromagnets. The scientists wrapped three-dimensional coils, with a width of 80 um, spacing of 100 um, and thickness of 25 um, 30 times around a permalloy core. They chose permalloy because it magnetizes and demagnetizes with low-magnetic field strength.

The type of DNA was likewise important to the study's success. The team used λ-phage DNA, which had two complementary 12-base, single-stranded 5' overhangs. "These overhangs allow phage DNA to easily be derivatized with various functional groups by base-pairing with a complementary sequence," Lee explained. Each base pair of DNA was 0.34nm, without any external force.

The scientists colored the DNA with a green dye, keeping the base pair to dye molecule ratio at 5 to 1, in order to have a high signal-to-noise ratio. "Since a DNA molecule only has a 2nm thickness, we can't observe it with a normal optical microscope," Lee said. The dye allowed the team to view DNA under a fluorescent microscope.

An important element to Lee's study was a microfluidic channel integrated with the magnetic tweezers. This channel had a width of 5mm, height of 60um, and length of 2cm. "We sealed the microfluidic channel with a glass cover slip (100um thick), using double-sided sticky tape (60um thick)."

"The microfluidic channel allowed us to observe a single DNA molecule in real-time," Lee stressed. "We introduced the DNA by pressuring it with a syringe pump into the channel."

Another element to the study was what to use on DNA extremities. "A DNA specific-end anchoring must meet several rigorous requirements, including specific binding, binding strength, localized binding, and complexity level of the procedure," Lee said... nano magnetic tweezers

New Material Could Have Applications For Microelectronics, Drug Delivery Systems

A new study by chemists and engineers at the University of Toronto describes a nanoscale material they’ve created that could help satisfy society’s never-ending hunger for smaller digital devices and cellphones, and could even lead to new methods for delivering medications via skin patches.

The material, known as periodic mesoporous organosilica (PMO), is a thin film interspersed with pores just two-billionths of a metre across. The team created it by mixing an organosilica precursor (silica glass, containing organic groups) with a surfactant — essentially, a soap that mixes oil and water — which causes the organosilica to self-assemble into a nanostructure. The scientists then washed away the surfactant to leave a nanoporous material. When they examined the thin film that remained, they discovered that it made an excellent insulator that could be used to separate tiny wires inside microelectronics.

“It demonstrates how creative chemistry can lead to really interesting engineering — it’s a good marriage,” says Benjamin Hatton, who led the work while he was a PhD candidate working with both the Departments of Chemistry, with supervisor Professor Geoffrey Ozin, and Materials Science and Engineering, with supervisor Professor Doug Perovic. “Technology can develop in unexpected ways, and what we’ve found here could lead to developments in microelectronics or drug delivery systems.”

Conventionally, computer chip manufacturers have insulated their wire connections with silica glass, preventing them from coming into contact and interfering, with each other. But the PMO film described in this study acts as a better insulator and would take up far less room, allowing components to shrink even further. “Industry is always looking for a better insulator,” Hatton says. “This is an example of how materials chemistry can provide innovative solutions to the design of novel materials.”... nanoscale materials

Nanoelectronics roadmap aims to speed commercialization

The IEEE launched an Nanoelectronics Standards Roadmap initiative Tuesday (March 21) to forge industry standards for nanotechnology.

The effort is designed to move nanoelectronics innovations from laboratory to the marketplace for applications ranging from communications, information technology, consumer products and optoelectronics.

IEEE will host a roadmap workshop on May 18 in New York to define the scope and timing of the standards.

Roadmap work will be led by a steering committee representing diverse segments of the nanoelectronics community, including materials and device developers, nanoelectronics integrators along with regulatory concerns.

The workshop, colocated with the Nano-Business Conference, will build on the IEEE-SA (Standards Association) nanoelectronic standards framework for nanomaterials, devices, functional blocks and applications. Plans call for a first draft of the roadmap for presentation at a second workshop in October and publication at the end of 2006. The roadmap will be updated annually.

According to Nathan Tinker, roadmap coordinator and co-founder of the Nano-Business Alliance trade organization, "The IEEE roadmap will help the industry prioritize the standards it needs and focus its resources." Tinker added that the roadmap will supplement other technology blueprints like the International Technology Roadmap for Semiconductors and the International Electronics Manufacturing Initiative.

IEEE-SA said a broad nanoelectronic roadmap builds on similar efforts targeting carbon nanotube technology. The 2003 effort yielded several standards activities, including the recently approved IEEE 1650, "Standard Test Methods for Measurement of Electrical Properties of Carbon Nanotubes." The first-ever nanoelectronics standard provides a common template for generating reproducible electrical data on nanotubes... via

First images of flowing nano ripples

TU Delft Researchers have shed new light on the formation of nanoscale surface features, such as nano ripples. These features are important because they could be useful as templates for growing other nanostructures. The scientific journal Physical Review Letters published an article this week on the research in Delft.

Some remarkable geometrical features may appear for instance on a glass surface when it is bombarded with ions, such as triangular patterns and ripples. Scientists study nano ripples and other geometrical features created by bombarding a surface with a beam of ions because of their potential as a template for growing other specific nanostructures. If they want to exploit this potential, they will first need a thorough understanding of the creation and evolution of geometrical features of this kind.

A scientific explanation of the ripples was given fifteen years ago. It was already known that surfaces wear quickly when they are bombarded. The erosion is stronger in the valleys of the ripples than in other places, so the valleys get deeper as time passes.

But the nano ripples do not continue to grow indefinitely. The bombardment liquefies the upper layer of the material, so that it flows from the peaks into the valleys.

No one has ever seen this actual flow until now, only the final result: the partly-filled ripple patterns. Dr Paul Alkemade, a researcher at the Kavli Institute of Nanoscience of Delft University of Technology became the first person to watch this flow using an electron microscope incorporating an ion beam... nano ripples

Nano Image of the Day - Mar 21st 2006

The "nano-flowers" are created by varying the temperature and pressure of a chemical process.

Tiny representations of flowers and trees that are a fraction of the width of a human hair have been created by scientists in Cambridge, UK.

The nano-sized plants are "grown" from tiny droplets of the liquid form of the metal gallium on a silicon surface.

The scientists then expose the droplets to a gas containing methane and a reaction causes the gas to condense to form tiny wires of silicon carbide.

The images appear in the Institute of Physics journal Nanotechnology.

By varying the temperature and pressure of the growth process the wires can be fused together to form a variety of complex shapes in the range of 1-5 microns (millionths of a metre)... source

The road to nanomedicine may not always be quick or easy

Of the six volunteers who became seriously ill during a drug trial last week, four, mercifully, seem to be beginning to recover, while two are still critical, according to the most recent BBC news story. It’s still too early to be sure what went so tragically wrong; there are informative articles, with some informed comment, on the websites both of New Scientist and Nature. What we should learn from this is that even as medicine gets more sophisticated and molecularly specific, many things can go wrong in the introduction of new therapies. The length of time it takes new treatments to get regulatory approval can be frustratingly, agonisingly long, but we need to be very careful about the calls we sometimes hear to speed these processes up. The delays are not just gratuitous red tape.

The drug behind this news story was developed by a small, German company, TeGenero immunotherapeutics. It’s a monoclonal antibody, code-named TGN1412; a protein molecule which specifically binds to a receptor molecule on T-cells, a type of white blood cell which is central to the body’s immune response. The binding site - code-named CD28 - is a glyco-protein - a combination of a protein with a carbohydrate segment - which provides the signal to activate the T-cells. What’s special about TGN1412 is that the action of this drug alone is sufficient to activate the T-cells; normally simultaneous binding to two different receptors is required. It’s as if TGN1412 overrides the safety catch, allowing the T-cells to be activated by a single trigger. It’s these activated T-cells that then carry out the therapeutic purpose, killing cancer cells, for example.

Few people have connected these events with bionanotechnology (an exception is the science journalist Niels Boeing in this piece on the German Technology Review blog). There are now a number of monoclonal antibody based drugs in clinical use, and they are not normally considered to be the product of nanomedicine... nanomedicine