Nanotechnology News

Moved to www.nanotechstate.com

2006-09-19T16:30:00.000-07:00

We got our own domain name www.nanotechstate.com, so from now on you can follow us there. All the articles that were here are already tranferred to Nano Tech State.

Researchers build tiny batteries with viruses

2006-04-07T07:43:00.000-07:00

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

2006-04-03T21:47:00.000-07:00

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

2006-04-01T13:17:00.000-07:00

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

2006-03-30T08:27:00.000-07:00

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

2006-03-29T10:06:00.000-07:00

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

2006-03-27T15:31:00.000-07:00

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

2006-03-27T09:42:00.000-07:00

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

2006-03-23T23:16:00.000-07:00

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

2006-03-23T17:06:00.000-07:00

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

2006-03-22T08:09:00.000-07:00

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

2006-03-21T08:06:00.000-07:00

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

2006-03-21T07:57:00.000-07:00

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

Virus used to make nanoparticles

2006-03-19T22:01:00.000-07:00

UK scientists from Norwich have used a plant virus to create nanotechnology building blocks.

The virus, which infects black-eyed peas, was employed as a "scaffold" on to which other chemicals were attached.

By linking iron-containing compounds to the virus's surface, the John Innes Centre team was able to create electronically active nanoparticles.

The researchers tell the journal Small that their work could be used in the future to make tiny electrical devices.

The work is yet another example of how scientists are now trying to engineer objects on the scale of atoms and molecules.

At the nanoscale, materials can be "tuned" to display unusual properties that could be exploited to build faster, lighter, stronger and more efficient devices and systems.

Stores charge

The mosaic virus used in the experiments infects black-eyed pea plants (Vigna unguiculata), causing their leaves to become mottled and yellow.

Not infectious to humans or animals, the miniscule virus measures just 30 nanometres across - where one nanometre is a billionth of a metre... virus used to make nanoparticles

A New Process Allows Growing Carbon Nanotubes Directly onto MEMS

2006-03-18T21:45:00.000-07:00

Researchers in Switzerland have successfully integrated carbon nanotubes (CNTs) directly into a polysilicon chip. This technique is opening the way towards NEMS and CNT based system integration and the synthesis and evaluation of mechanical nano-scale transducers based on CNTs.

Researchers in Switzerland have successfully integrated carbon nanotubes (CNTs) directly into a polysilicon chip. This technique is opening the way towards NEMS and CNT based system integration and the synthesis and evaluation of mechanical nano-scale transducers based on CNTs.

The group reports their findings titled "Process integration of carbon nanotubes into microelectro- mechanical systems" (article in press) in the Jan.20, 2006 online edition of Sensors and Actuators A: Physical. In this paper they describe the process flow and characterization of their novel approach to integrate nanotube growth into batch fabricated MEMS.

Alain Jungen, researcher and author of the study and Christofer Hierold, professor of Micro- and Nanosystems at the ETH Zurich, explained:

"In our paper we demonstrate a new process allowing direct synthesis of carbon nanotubes onto MEMS. The MEMS chips were successfully post-processed with electron beam lithography combined with lift-off of catalyst layers."

"With our novel process, individual or multiple tubes can be directly grown between movable posts and electrically connected. This way direct and reliable measurement techniques can be developed and used to accelerate research and evaluation of nanotube transducer properties."

CNTs are arguably the most studied nanomaterials in recent years due to their fascinating physical properties. Apart from their hardness and toughness they have demonstrated exceptionally high thermal conductivity, eventually exhibiting a property known as "ballistic conduction." This makes them ideal candidates for highly integrated electromechanical nanosystems (NEMS).

In developing NEMS major challenges still need to be overcome, foremost controlled and reproducilble integration of the tubes by local growth or self-assembly and the fundamental characterization of electromechanical effects in carbon nanotubes. Only then can CNT-based NEMS become a reality.

A research project in Hierold's group, called "Integrated nano transducers: fundamental characterization of electromechanical effects in carbon nanotubes" is focussing on exactly this problem area... via

UCR Researchers Grow Bone Cells on Carbon Nanotubes

2006-03-17T18:12:00.000-07:00

Researchers at the University of California, Riverside have published findings that show, for the first time, that bone cells can grow and proliferate on a scaffold of carbon nanotubes.

The paper, titled Bone Cell Proliferation on Carbon Nanotubes, appears in the March 8 edition of Nano Letters, a journal of the American Chemical Society. Lead author, Laura Zanello, is an assistant professor of biochemistry at UCR and was joined by UCR colleagues, graduate students Bin Zhao and Hui Hu, and Robert C. Haddon, distinguished professor of chemistry and of chemical and environmental engineering.

Zanello’s paper builds on previous research by Haddon which showed that carbon nanotubes could be chemically compatible with bone cells.

Zanello’s experiment put Haddon’s findings to the test and found that the nanotubes, 100,000 times finer than a human hair, are an excellent scaffold for bone cells to grow on.

“In the past scientists have been plagued by toxicity issues when combining carbon nanotubes with living cells,” Zanello said. “So we have been looking for the most pure nanotubes we could get to reduce the presence of heavy metals that are frequently introduced in the manufacturing process.”

She credited Haddon’s graduate student Zhao, now a postgraduate researcher at the Oak Ridge National Laboratory, with manufacturing highly pure nanotubes for her to work with.

Some of the carbon nanotubes were chemically treated and others were not, then they were combined with rat bone cells to determine which combination or combinations worked best. Non-treated and electrically-neutral nanotubes emerged as the best scaffolds for bone growth.

Because carbon nanotubes are not biodegradable, they behave like an inert matrix on which cells can proliferate and deposit new living material, which becomes functional, normal bone, according to the paper. They therefore hold promise in the treatment of bone defects in humans associated with the removal of tumors, trauma, and abnormal bone development and in dental implants, Zanello added.

More research is needed to determine how the body will interact with carbon nanotubes, specifically in its immune response, the paper states.

“We hope to look at the atomic interactions between living matter and synthetic scaffolds so we can come up with material that can interact at the nanolevel with living cells,” Zanello said... bone cells grow on carbon nanotubes

Nanotech discovers the Americas

2006-03-16T13:55:00.000-07:00

It is without question the smallest map that has ever been made.

US scientists have coaxed strands of DNA, the molecule that holds the "code of life", to take up a shape that resembles the Americas.

The mini-map measures just a few hundred nanometres (billionths of a metre) across, smaller even than some bacteria - a scale of 1:200 trillion.

Paul Rothemund, from the California Institute of Technology, and colleagues report their cartography in Nature.

They tell the journal their technique could find uses in the emerging field of nanotechnology, which aims to develop novel materials, devices and systems by manipulating individual atoms and molecules.

The team's work exploits the very particular bonding that takes place in DNA.

Each strand of the molecule will have a sequence of chemical components, or bases, which will only attach themselves to a complementary code of another DNA strand (see box).

The researchers made long single strands of DNA that could be folded back and forth, tracing a mazelike path, to form a scaffold that filled up the outline of any desired shape. new method for folding DNA strands

Rice University researchers create 'nanorice'

2006-03-15T09:30:00.000-07:00

Who better to invent "nanorice" than researchers at Rice University? But marketing and whimsy weren't what motivated the team of engineers, physicists and chemists from Rice's Laboratory for Nanophotonics (LANP) to make rice-shaped particles of gold and iron oxide.

"On the nanoscale, the shape of a particle plays a critical role in how it interacts with light," said LANP Director Naomi Halas. "We were looking for a new shape that would combine the best properties of the two most optically useful shapes – spheres and rods. It's just a coincidence that that shape turned out to look exactly like a grain of rice."

Nanoparticles like nanorice can be used to focus light on small regions of space. Rice's scientists plan to capitalize on this by attaching grains of nanorice to scanning probe microscopes. By moving the grains next to proteins and unmapped features on the surfaces of cells, they hope to get a far clearer picture than what's available with current technology.

The nanorice research will appear in the April 12 issue of Nano Letters. Halas will discuss the findings at 11:30 a.m. today at a press conference at the American Physical Society's 2006 March Meeting in room 334 of the Baltimore Convention Center.

In form, nanorice is similar to nanoshells, a spherical nanoparticle Halas invented in 1998 that is currently being examined for possible applications in molecular imaging, cancer treatment, medical diagnostics and chemical sensing. Both nanorice and nanoshells are made of a non-conducting core that is covered by a metallic shell.

Halas' investigations find that nanorice possesses far greater structural tunability than nanoshells and another commonly studied optical nanoparticle, the nanorod. In fact, tests indicate that nanorice is the most sensitive surface plasmon resonance (SPR) nanosensor yet devised.

Research over the past decade has shown that nanoscale objects can amplify and focus light in ways scientists never imagined. The "how" of this involves plasmons, ripples of waves in the ocean of electrons that flow constantly across the surfaces of metals. When light of a specific frequency strikes a plasmon that oscillates at a compatible frequency, the energy from the light is converted into electrical energy that propagates, as plasmons, through the nanostructure.

Changing the shape of a metal at the nanoscale allows engineers and scientists to modify the properties of these plasmon waves, controlling the way that the metal nanostructure responds to light. Because of this, metal nanostructures can have beautiful, vivid colors that depend on their shape. Some nanoscale structures -- like nanorice and nanoshells -- act as superlenses that can amplify light waves and focus them to spot sizes far smaller than a wavelength of light.

In January 2005, for example, Halas and colleagues showed that nanoshells were about 10,000 times more effective at Surface-enhanced Raman Scattering (SERS) than traditional methods. Raman scattering is a type of spectrographic technique used by medical researchers, drug designers, chemists and others to determine the precise chemical makeup of materials... nanorice

Nanotech helps blind hamsters see

2006-03-14T09:56:00.000-07:00

Nanotechnology has restored the sight of blind rodents, a new study shows.

Scientists mimicked the effect of a traumatic brain injury by severing the optical nerve tract in hamsters, causing the animals to lose vision.

After injecting the hamsters with a solution containing nanoparticles, the nerves re-grew and sight returned.

Writing in the Proceedings of the National Academy of Sciences, the team hopes this technique could be used in future reconstructive brain surgery.

Ultimate challenge

Repairing nerve damage in the central nervous system after injury is seen as the ultimate challenge for neuroscientists, but so far success in this field has been limited.

Nerve regeneration is set back by a number of factors, including scar tissue and gaps in brain tissue caused by the damage. And this can make treatment by medical and surgical methods very difficult.

To find a novel way around these problems, the team based at Massachusetts Institute of Technology (MIT), US, and Hong Kong University looked towards nanotechnology - a branch of science involving the manipulation of atoms and molecules.

The researchers injected the blind hamsters at the site of their injury with a solution containing synthetically made peptides - miniscule molecules measuring just five nanometres long.

Once inside the hamster's brain, the peptides spontaneously arranged into a scaffold-like criss-cross of nanofibres, which bridged the gap between the severed nerves... nanotechnology helps blind hamsters

I, Nanobot

2006-03-13T17:07:00.000-07:00

A pessimistic as well as a futuristic article by Alan H. Goldstein. An interesting read I must say. And I don't agree with 99% of what is said in there...

...In fact, we have put into motion research that will create every component necessary to build an animat. One formula is as simple as A + B + C.

A = Nanobiotechnology devices that can survive and function inside human beings. Many therapeutic devices in development for drug delivery, cancer therapy, etc., are designed to survive in the physicochemical environment of the body.

B = Nanobiotechnology devices that can derive energy from biological metabolism. Many nanomedical devices will be powered by the fuel available inside the human body. A common idea is to take our own glucose-oxidizing enzymes and use them as a fuel cell for the nanobiobot.

C = Nanobiotechnology devices capable of copying themselves by molecular self-assembly.

Which creates a completely realistic animat formula. A + B + C = a self-replicating nanobiobot capable of living inside the human body powered by our own metabolic energy.

Of course, scientists are not intentionally putting A together with B and C. No one is trying to create the first true animat -- they're just working on rudimentary forms of artificial life or synthetic biology. But if, as part of this benign research initiative, they happen to create nanobiobots some of which have traits A or B or C -- our definition of life will have changed forever.

Does this mean we will immediately cease to be human? Probably not. The most probable scenario is that an array of proto-animats will be carried as an evolutionary adaptation that enhances biological function for generations before any of them become an essential part of our phenotype. After that...

If the animat test described here is not sufficient, let it stand as a challenge for the development of a completely rigorous test for the unequivocal identification of nonbiological life forms. The larger point is that humanity must initiate a search-and-test protocol now in order to prepare for the arrival of the literal alien from within.

Nanofabricated animats may be infinitessimally tiny, but their electrons will be exactly the same size as ours -- and their effect on human reality will be as immeasurable as the universe. Like an inverted SETI program, humanity must now look inward, constantly scanning technology space for animats, or their progenitors. The first alien life may not come from the stars, but from ourselves. read

Canine Parvovirus-Like Particles, A Novel Nanomaterial for Tumor Targeting

2006-03-12T17:17:00.000-07:00

Empty virus particles have shown promise as potential nanoscale drug carriers that can be modified chemically to display tumor-targeting molecules (click here for earlier story). Now, investigators at The Scripps Research Institute have shown that canine parvovirus nanoparticles, which bind to a receptor that is overproduced by some types of malignant cells, will naturally target tumors.

Writing in the Journal of Nanobiotechnology, a team led by Marianne Manchester, Ph.D., describes its studies aimed at determining whether mass-produced, non-infectious canine parvovirus nanoparticles might be suitable as a tumor-targeting drug delivery vehicle through the particles’ natural interaction with transferrin, a receptor that carries iron into cells. The reproducible size and chemical makeup of virus-based nanoparticles, combined with the relative ease of manufacturing them in large quantities, make them possible winners in the drive to develop nanoparticulate drug carriers for cancer therapy. Such laudable properties are only of use, however, if these protein nanoparticles can be modified to carry small molecules into tumor cells.

The investigators began by analyzing the structure of protein that assembles into viral nanoparticles. This evaluation showed that there should be at least two, and perhaps as many as six, amino acids on the surface of this protein that should be available to react chemically with small drug molecules or imaging agents. Since 60 copies of this protein come together to form the final virus nanoparticle, the investigators reasoned that it should be relatively straightforward to attach clinically useful molecules to the virus nanoparticles... via

Nanotechnology Could Improve Satellites and Solar Cells

2006-03-11T13:58:00.000-07:00

More efficient space solar cells could mean better imagery satellites and improved solar energy technology.

Scientists at the NanoPower Research Labs at Rochester Institute of Technology, led by director Ryne Raffaelle, are using nanotechnology to explore this possibility through a project funded by an $847,109 grant from the U.S. Department of Defense. The project aims to take current state-of-the-art solar cells used for space power to the next level by developing nanostructured materials and, ultimately, by producing nanostructured cells. The program may extend to three and half years, with total funding reaching $3 million.

“If successful, the results of this program will improve current solar array and satellite technology, and lay the foundation for long-term improvement in our ability to use solar energy,” Raffaelle says.

Unique to this project is the ability to exploit the fundamental behavior of nanoscale crystals, also known as quantum dots, which alter the way a solar cell absorbs light and converts it into electricity. According to Raffaelle, the electrical, optical, mechanical and even thermal properties of nanomaterials can be controlled by changing the particle size, making them highly useful in semiconductor device development.

Today’s current solar-cell technology used for space power relies upon three individual photovoltaic junctions used in a series. These so-called triple-junction solar cells—consisting of the chemical compounds, germanium, gallium arsenide and indium gallium phosphide—are grown latticed-matched on top of one another. Raffaelle’s team will augment the middle cell in the three-layered sandwich with a quantum dot array to enhance its short-circuit current and improve the overall efficiency of the triple junction cell... space solar cells

Nano Image of the Day - Mar 10th 2006

2006-03-10T11:37:00.000-07:00

Transmission electron microscopy shows nano-sized particles that form when fullerenes clump together in water. Research is showing what factors affect particle size.

Fate of Nano Waste: Researchers Study How to Make Nanomaterial Industry Environmentally Sustainable
... Researchers picked fullerenes, molecules composed of 60 carbon atoms, as their model carbon-based nanomaterial. Fullerenes have a potentially broad range of applications, including their use in pharmaceuticals, as lubricants, as semiconductors and in energy conversion. Mass commercial production of fullerenes may get under way internationally in just two years.

“This research is providing the information to make practices sustainable when fullerene production comes on line,” said John Fortner, a Georgia Tech research scientist and Rice University Ph.D. student. “It’s our goal to minimize environmental impact in contrast to the pollution caused in the past by, for example, dry cleaning industry practices... nanowaste

Experimental Atomic Clock Uses Ytterbium ‘Pancakes’

2006-03-10T11:31:00.000-07:00

Scientists at the National Institute of Standards and Technology (NIST) working with Russian colleagues have significantly improved the design of optical atomic clocks that hold thousands of atoms in a lattice made of intersecting laser beams. The design, in which ytterbium atoms oscillate or “tick” at optical frequencies, has the potential to be more stable and accurate than today’s best time standards, which are based on microwaves at much lower frequencies. More accurate time standards could improve communications, enhance navigation systems, and enable new tests of physical theories, among other applications.

Described in two papers in the March 3 issue of Physical Review Letters,* the heart of the clock consists of about 1,000 pancake-shaped wells made of laser light and arranged in a single line, each containing about 10 atoms of the heavy metal ytterbium. The lattice design results in fewer systematic errors than optical atomic clocks using moving balls of cold atoms, and also offers advantages in parallel processing over other approaches using single charged atoms (ions). The optical lattice, created by an intense near-visible laser beam, is loaded by first slowing down the atoms with violet laser light and then using green laser light to further cool the atoms so that they can be captured. Scientists detect the atoms’ “ticks” (518 quadrillion per second) by bathing them in yellow light at slightly different frequencies until they find the exact “resonant” frequency (or color) that the atoms absorb best.

Previous lattice-based clocks have used atoms with odd-numbered atomic masses, which have a nuclear magnetic field that causes some additional complications. The new clock uses atoms with even-numbered atomic masses that have no net nuclear magnetic field but have been difficult to use in atomic clocks until now. The researchers found they could apply a small external magnetic field combined with yellow laser light to induce an otherwise “forbidden” oscillation between two energy levels in the atoms. The team reported an extremely precise resonance frequency with a strong signal that demonstrates the clock’s potential for very high stability. The new approach is also applicable to other atoms with even-numbered atomic masses, such as strontium and calcium, which are under study at NIST and other research laboratories around the world... atomitc clock with ytterbium

Nanoparticles create biocompatible capsules

2006-03-08T08:39:00.000-07:00

An innovative strategy of mixing lipids and nanoparticles to produce new drug and agricultural materials and delivery vehicles has been developed by researchers at the University of Illinois at Urbana-Champaign.

“This is a new way to make nano-size capsules of a biologically friendly material,” said Steve Granick, a professor of materials science and engineering, chemistry and physics. “The hollow, deformable and biofunctional capsules could be used in drug delivery, colloidal-based biosensors and enzyme-catalyzed reactions.”

Lipids are the building blocks of cell membranes. The construction of useful artificial lipid vesicles was previously not possible, because the vesicles were too delicate. Granick and graduate student Liangfang Zhang found a way to stabilize lipids and stop their destruction. The researchers describe their technique in a paper accepted for publication in the journal Nano Letters, and posted on its Web site.

To stabilize lipids, the researchers begin by preparing a dilute solution of lipid capsules of a particular size. After encapsulating chemicals in the capsules or adsorbing molecules on their surfaces, they add charged nanoparticles to the solution. The nanoparticles adhere to the capsules and prevent further growth, freezing them at the desired size. The lipid concentration can then be increased without limits.... biocompatible nano capsules