Wednesday, May 7, 2008
HYDROCHALARONE MRI Contrast Agent Does Well in Early Study
HYDROCHALARONE™ nanomaterial is a next generation contrast agent, under development by Roanoke, Virginia based firm Luna Innovations, that has just been successfully demonstrated as an effective MRI image enhancer in the mouse model. HYDROCHALARONE is based on the company's proprietary TRIMETASPHERE® molecular cage construct (second picture below), a molecule formed by up to 80 carbon atoms, that is capable of encapsulating a variety of metals (Scandium, Lutetium, Holmium, Gadolinium) inside its cage.
From the press statement by Luna Innovations:
The new class of molecules discovered by Luna is called HYDROCHALARONE(TM) ( hi-dro-kal-a-rone )-- Hydro, meaning water, combined with Chalaro, the Greek word for relax. The level of relaxivity is the characteristic of molecules that provides the image enhancement. "The high relaxivity in Hydrochalarone means fewer molecules are needed to obtain a better quality image," said Robert Lenk, President of Luna's nanoWorks division. "Our studies demonstrate that our proprietary nanomaterials do not release gadolinium under conditions which are found in the human body. Our imaging studies in mice have shown Hydrochalarone improves image quality up to 30 minutes after injection at a dose 20 times lower than that used with current agents."
"Achieving high magnetic resonance relaxivity with a small, biologically inert, chemical moiety that can be derivatized for targeted tissue delivery, cell tracking, or inclusion as part of a nanoparticle drug delivery vehicle is a Holy Grail within the fast evolving field of biomarker development," said Dr. Joseph Ackerman renowned MRI researcher and Chemistry Department Chairman at Washington University in St. Louis. "The design and production of Hydrochalarones by scientists at Luna nanoWorks may herald such an advance."
Luna's HYDROCHALARONE(TM) was selected for preclinical studies and a collaboration with National Cancer Institute's Nanotechnology Characterization Laboratory (NCL). "We hope within 12 months the NCL will provide us a complete preclinical package which will contribute to an Investigational New Drug application," said Lenk. "The end goal of Luna's product development effort with the Hydrochalarone is using it as a fundamental building block that will generate a portfolio of novel imaging agents targeted to reveal diagnostic information specific for a variety of different diseases, such as cancer tumors, sites of inflammation and plaque related to coronary artery diseases, as announced in our previous press release."
Product page: Luna's HYDROCHALARONE...
Press release: Luna Innovations Successfully Demonstrates MRI Contrast Agent...
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Monday, May 5, 2008
Micro Drug Packaging Out of Origami
At the University of Southern California's Information Sciences Institute, researchers have developed an origami-like technique to fold sheets of silicon and gold into 3D enclosing shapes such as the 30 micrometer pyramid above. The scientists hope the technology will one day allow for a new mechanism of transporting drugs through the body.
Press release: Mini-Origami: ISI Folds Up Tiny Packages for Drug Delivery
(hat tip: Gizmodo)
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Wednesday, April 23, 2008
Measurement Issues in Single Wall Carbon Nanotubes
The National Institute of Standards and Technology (NIST), in collaboration with NASA, has published a white paper that details how to standardize measurements of single-walled carbon nanotubes (SWCNTs) for researchers and the industry. SWCNTs are known to be an extremely promising bionanomaterial, as our archives rightly testify.
The new guide constitutes the current “best practices” for characterizing one of the most promising and heavily studied of the new generation of nanoscale materials.The nanotubes are essentially cylinders of carbon atoms with a wall only one atom thick and a diameter of a couple of nanometers—but lengths up to several million times their diameter. (Think of a soup can about 100 kilometers tall.) Because of their unique electronic, thermal, optical and mechanical properties they are being studied for a wide—and expanding—range of applications, including ultrastrong fibers for nanocomposite materials, circuit elements in molecular electronics, hydrogen storage components for fuel cells and light sources for compact, efficient flat-panel displays. One basic problem is assuring the quality and purity of SWCNT materials. All known techniques for producing these tiny tubes also produce large quantities of nanojunk: simple graphite and carbon soot often encapsulating small metal particles used to catalyze the nanotube synthesis process.
Accurate, reliable and preferably rapid measurement techniques are needed to optimize production processes to create more product and less impurities. These will help to control cleaning and purifying processes and ultimately to improve the confidence of buyers and sellers of SWCNT materials. Beginning in 2003, NIST and NASA researchers started addressing the problem by sponsoring a series of workshops devoted to nanotube measurements. The NIST “Recommended Practice Guide” on Measurement Issues in Single Wall Carbon Nanotubes grew out of second workshop in 2005, and represents what industry, government and academic researchers regard as the most useful and accurate measurement techniques for characterizing the purity of SWCNT samples. The techniques discussed include thermogravimetric analysis; near-infrared spectroscopy; Raman spectroscopy and optical, electron and scanned probe microscopy. Researchers from the NASA Johnson Space Center, the University of California at Riverside, Boston University and the NASA Langley Research Center contributed to the guide.
Full paper below:
Carbon Nanotube Measurements: Latest in NIST 'How-To' Series...
The "How To Measure" Book Series...
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Friday, April 18, 2008
Guiding Monocytes with Nanomagnets
Potentially allowing for more effective gene therapy techniques of the future, British researchers were able to inject nanomagnets into monocyte cells, and guide them toward tumor sites:
Using human cells as delivery vehicles for anti-cancer gene therapy has long been an attractive approach for treating tumours, but these cells usually reach tumours in insufficient numbers to effectively attack them. Now, a new 'magnetic targeting' method has been developed to overcome this problem by Professor Claire Lewis at the University of Sheffield, Professor Jon Dobson at the University of Keele, and Professor Helen Byrne and Dr. Giles Richardson at the University of Nottingham.The technique involves inserting nanomagents into monocytes - a type of white blood cell used to carry gene therapy - and injecting the cells into the bloodstream. The researchers then placed a small magnet over the tumour to create a magnetic field and found that this attracted many more monocytes into the tumour.
The head of the laboratory in which the work was done, Professor Lewis, explains: "The use of nanoparticles to enhance the uptake of therapeutically armed cells by tumours could herald a new era in gene therapy - one in which delivery of the gene therapy vector to the diseased site is much more effective. This new technique could also be used to help deliver therapeutic genes in other diseases like arthritic joints or ischemic heart tissue."
Professor Jon Dobson from the University of Keele, said: "Though the concept of magnetic targeting for drug and gene delivery has been around for decades, major technical hurdles have prevented its translation into a clinical therapy. By harnessing and enhancing the monocytes' innate targeting abilities, this technique offers great potential to overcome some of these barriers and bring the technology closer to the clinic."
Press release: Tiny magnets offer breakthrough in gene therapy for cancer
Image credit: Wellcome images: Monocyte and two red blood cells...
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Nanodrop Test Tube for Study of Intracellular Proteins
Intracellular proteins are all naturally cramped up in the restrictive confines of the cell. So, probably the best way to study them is under similar physiological circumstances. At least that's what investigators from the National Institute of Standards and Technology think:
Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a new device that creates nanodroplet “test tubes” for studying individual proteins under conditions that mimic the crowded confines of a living cell. “By confining individual proteins in nanodroplets of water, researchers can directly observe the dynamics and structural changes of these biomolecules,” says physicist Lori Goldner, a coauthor of the paper published in Langmuir.Researchers recently have turned their attention to the role that crowding plays in the behavior of proteins and other biomolecules—there is not much extra space in a cell. NIST’s nanodroplets can mimic the crowded environment in cells where the proteins live while providing advantages over other techniques to confine or immobilize proteins for study that may interfere with or damage the protein. This more realistic setting can help researchers study the molecular basis of disease and supply information for developing new pharmaceuticals. For example, misfolded proteins play a role in many illnesses including Type 2 diabetes, Alzheimer’s and Parkinson’s diseases. By seeing how proteins fold in these nanodroplets, researchers may gain new insight into these ailments and may find new therapies.
The NIST nanodroplet delivery system uses tiny glass micropipettes to create tiny water droplets suspended in an oily fluid for study under a microscope. An applied pressure forces the water solution containing protein test subjects to the tip of the micropipette as it sits immersed in a small drop of oil on the microscope stage. Then, like a magician whipping a tablecloth off a table while leaving the dinnerware behind, an electronic switch causes the pipette to jerk back, leaving behind a small droplet typically less than a micrometer in diameter.
The droplet is held in place with a laser “optical tweezer,” and another laser is used to excite fluorescence from the molecule or molecules in the droplet. In one set of fluorescence experiments, explains Goldner, “The molecules seem unperturbed by their confinement—they do not stick to the walls or leave the container—important facts to know for doing nanochemistry or single-molecule biophysics.”
Press release: 'Nanodrop' Test Tubes Created with a Flip of a Switch...
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Monday, April 14, 2008
Nanoparticles As Hearing Aids
NanoBioMagnetics, Inc. of Edmond, Oklahoma has received a patent for using metallic nanoparticles as the main component for creating a hearing aid system.
The patent, titled “Method and Apparatus for Improving Hearing,” is based on the use of magnetically responsive nanoparticles implanted in the organs of the middle ear to drive tissue vibrations in the amplification of sound. The technology was the first demonstration of the nanomechanical movement of tissue and operates in principle much like a typical commercial electromagnetic hearing aid. Development and validation was done during 2002 - 2004. The company now will move the technology through commercialization partnerships.Statistics of the National Institutes of Health indicate sensorineural hearing loss affects approximately 28 million Americans. The technology covered by today’s patent has the potential to move hearing aid systems to smaller and totally implantable hearing devices, achieving more favorable patient economics, performance and compliance.
Press release (PDF): NanoBioMagnetics Announces Issuance of US Patent
Patent application at USPTO...
Company page: NanoBioMagnetics, Inc.
(hat tip: The Engineer Online)
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Friday, April 11, 2008
Nanotechnology Solutions for Alzheimer's Disease
Our friend Michael Berger at Nanowerk has an interesting article that looks at how the development of nanotechnology might improve diagnosis and treatment of Alzheimer's disease: Nanotechnology solutions for Alzheimer's disease.
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Nanoparticles from Ivy and the Future of Medical Devices
Investigators from University of Tennessee and Agilent Labs, a firm out of Santa Clara, CA, were trying to figure out a molecular mechanism behind common ivy's ability to attach itself to the walls. The idea is that this knowledge might open possibilities for biomedical applications, such as new bioglues, sutures, or surgical adhesives.
Here's a synopsis of what the scientists have discovered, taken from the abstract:
Using atomic force microscopy, we observed ivy secretes nanoparticles through adhering disks of the ivy aerial rootlets which allow the plant to affix to a surface. We analyzed the organic composition of the secretions using high-performance liquid chromatography/mass spectrometry and were able to determine the formula of 19 compounds. This study suggests that the nanoparticles play a direct and important role for ivy surface “climbing”. Weak adhesion and hydrogen bonding seem to be the forces for the climbing mechanism. This ivy secretion mechanism may inspire new methods for synthesizing nanoparticles biologically or new approaches to adhesion mechanisms for engineering applications.
Read the whole article in Nano Letters: Nanoparticles Secreted from Ivy Rootlets for Surface Climbing
Flickr image by tashland: Little feet...
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Thursday, April 3, 2008
Scientists Develop Anti-Angiogenesis Nanoparticles
Investigators from the Washington University School of Medicine in St. Louis have developed nanoparticles laden with fumagillin, an angiogenesis inhibitor, known to be extremely neurotoxic in systemic dose. When given to tumor-bearing rabbits, the nanoconstructs were shown to be very effective in suppressing the neovasculature and inhibiting adenocarcinoma development, in concentrations way below a toxic dose:
"Many chemotherapeutic drugs have unwanted side effects, and we've shown that our nanoparticle technology has the potential to increase drug effectiveness and decrease drug dose to alleviate harmful side effects," says lead author Patrick M. Winter, Ph.D., research assistant professor of medicine and biomedical engineering.The nanoparticles are extremely tiny beads of an inert, oily compound that can be coated with a wide variety of active substances. In an article published online in The FASEB Journal, the researchers describe a significant reduction of tumor growth in rabbits that were treated with nanoparticles coated with a fungal toxin called fumagillin. Human clinical trials have shown that fumagillin can be an effective cancer treatment in combination with other anticancer drugs.
In addition to fumagillin, the nanoparticles' surfaces held molecules designed to stick to proteins found primarily on the cells of growing blood vessels. So the nanoparticles latched on to sites of blood vessel proliferation and released their fumagillin load into blood vessel cells. Fumagillin blocks multiplication of blood vessel cells, so it inhibited tumors from expanding their blood supply and slowed their growth.
Human trials have also shown that fumagillin can have neurotoxic side effects at the high doses required when given by standard methods. But the fumagillin nanoparticles were effective in very low doses because they concentrate where tumors create new blood vessels. The rabbits that received fumagillin nanoparticles showed no adverse side effects.
Senior author Gregory M. Lanza, M.D., Ph.D., associate professor of medicine and of biomedical engineering, and Samuel A. Wickline, M.D., professor of medicine, of physics and of biomedical engineering, are co-inventors of the nanoparticle technology. The nanoparticles measure only about 200 nanometers across, or 500 times smaller than the width of a human hair. Their cores are composed mostly of perfluorocarbon, a safe compound used in artificial blood.
The nanoparticles can be adapted to many different medical applications. In addition to carrying drugs to targeted locations, they can be manufactured to highlight specific targets in magnetic resonance imaging (MRI), nuclear imaging, CT scanning and ultrasound imaging.
Washington University School of Medicine in St. Louis: Nano-sized technology has super-sized effect on tumors...
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Tuesday, April 1, 2008
Light Activated Drug Nanotransporters
Using clever technology and special chemicals, UCLA scientists were able to create unique transport intracellular nanoparticles, motorized by 'nanoimpellers', that can be manually activated to release their cargo with a switch of a light, potentially allowing for precise targeting of drugs directly to the tumor. The nanoparticles are based on mesoporous silica, an interesting material seen on these pages before.
UCLA researchers used mesoporous silica nanoparticles and coated the interiors of the pores with azobenzene, a chemical that can oscillate between two different conformations upon light exposure. Operation of the nanoimpeller was demonstrated using a variety of human cancer cells, including colon and pancreatic cancer cells. The nanoparticles were given to human cancer cells in vitro and taken up in the dark. When light was directed at the particles, the nanoimpeller mechanism took effect and released the contents.The pores of the particles can be loaded with cargo molecules, such as dyes or anticancer drugs. In response to light exposure, a wagging motion occurs, causing the cargo molecules to escape from the pores and attack the cell. Confocal microscopic images showed that the impeller operation can be regulated precisely by the intensity of the light, the excitation time and the specific wavelength.
"We developed a mechanism that releases small molecules in aqueous and biological environments during exposure to light," Zink said. "The nanomachines are positioned in molecular-sized pores inside of spherical particles and function in aqueous and biological environments."
Press release: Nanoimpeller' releases anticancer drugs inside of cancer cells...
Abstract in Light-Activated Nanoimpeller-Controlled Drug Release in Cancer Cells...
Image credit: Oliver Burston, Wellcome Images: Artist's conception of nanoparticles...
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Monday, March 31, 2008
Two-Photon Nanoparticles for Tumor Recognition
A porous nanoparticle "capable of absorbing the energy of two photons in the near infrared spectrum, and then re-emitting radiation used for medical imaging by fluorescence" has been developed by an interdisciplinary group of scientists, reports Centre National de la Recherche Scientifique of France:
At present, the medical imaging of tumor cells is based on the fluorescence emitted by chemical groups that can absorb the energy of a photon. These molecules, called fluorophores, are excited in the visible ultraviolet spectrum. Single-photon imaging thus remains relatively imprecise. This obstacle should soon be overcome thanks to work by scientists from CNRS-associated laboratories.These researchers have succeeded in developing organic, two-photon fluorophores (aromatic molecules) that are able simultaneously to absorb two photons in the near infrared spectrum. These were then encapsulated in porous nanoparticles to enable their circulation in a biological medium. The originality of this work resides in the fact that unlike ultraviolet wavelengths, infrared wavelengths penetrate more deeply into tissues and are less energetic, the advantage being that they can explore tumors more profoundly without damaging the tissues. Furthermore, the use of two-photon fluorophores favors access to a 3D spatial resolution, which in the longer term will enable the detection and more targeted treatment of tumor cells. One of the options envisaged may be to encapsulate in the pores of silicon nanoparticles not only the fluorescent agent but also drugs that can locally treat the cancer cells.
The scientists have also been focusing on the functionalization of these nanoparticles in order to create new biological markers capable of interacting with breast and cervical cancer cells. To achieve this, they grafted on the nanoparticles a monolayer made up of a hydrophilic polymer (PEG: polyethylene glycol) and folic acid. The latter forms the ligand recognized by the receptors of HeLa cells (cervical cancer) and MCF7 cells (breast cancer) (see diagram). These results should enable the 3D targeting and imaging of the tumor. Other functionalizations could be envisaged, enabling the detection of other tumors.
Link: Two-photon nanoparticles for the improved detection of tumor cells...
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Wednesday, March 26, 2008
Researchers Show How Nanomaterials Misbehave
Call us nanoaddicts (the first time this medical term is being coined), but we get excited any time we see nanomaterial display properties that might come handy for the development of devices 200 years from now.
From the National Institute of Standards and Technology
In yet another twist on the strangeness of the nanoworld, researchers at the National Institute of Standards and Technology (NIST) and the University of Maryland-College Park have discovered that materials such as silica that are quite brittle in bulk form behave as ductile as gold at the nanoscale. Their results may affect the design of future nanomachines.NIST scientists Pradeep Namboodiri and Doo-In Kim and colleagues first demonstrated the latest incongruity between the macro and micro worlds this past fall with direct experimental evidence for nanoscale ductility. In a new paper presented today at the March Meeting of the American Physical Society, NIST researchers Takumi Hawa and Michael Zachariah and guest researcher Brian Henz shared the insights they gained into the phenomenon through their computer simulations of nanoparticle aggregates.
At the macroscale, the point at which a material will fail or break depends on its ability to maintain its shape when stressed. The atoms of ductile substances are able to shuffle around and remain cohesive for much longer than their brittle cousins, which contain faint structural flaws that act as failure points under stress.
At the nanoscale, these structural flaws do not exist, and hence the materials are nearly “perfect.” In addition, these objects are so small that most of the atoms that comprise them reside on the surface. According to Namboodiri and Kim, the properties of the surface atoms, which are more mobile because they are not bounded on all sides, dominate at the nanoscale. This dominance gives an otherwise brittle material such as silica its counterintuitive fracture characteristics.
“The terms ‘brittle’ and ‘ductile’ are macroscopic terminology,” Kim says. “It seems that these terms don’t apply at the nanoscale.”
Using an atomic force microscope (AFM), Kim and Namboodiri were able to look more closely at interfacial fracture than had been done before at the nanoscale. They found that the silica will stretch as much as gold or silver and will continue to deform beyond the point that would be predicted using its bulk-scale properties.
Hawa, Henz and Zachariah’s simulations reaffirmed their study and added some additional details. They showed that both nanoparticle size and morphology—whether the material is basically crystalline or amorphous, for example—have an effect on the observed ductility and tensile strength because those factors influence the mobility of surface atoms. In the simulations, the smaller the particles in the aggregate the more ductile the material behaved. Crystalline structures exhibited greater strength when stressed and deformed long after the critical yield point observed macroscopically.
Namboodiri explained that although the work is very basic, these findings might one day inform the design of microelectronic mechanical devices.
Nanomaterials Show Unexpected Strength Under Stress...
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Wednesday, March 19, 2008
Biofunctionalized Lipid-Polymer Hybrid Nanocontainers with Controlled Permeability
Nanowerk is reporting that a group of Dutch scientists developed biohybrid nanocontainers with controlled permeability, designed to enclose all sorts of biomolecules. Dr. Alma Dudia and colleagues (BMTI Institute for Biomedical Technology and MESA+ Institute for Nanotechnology at the University of Twente and BioMaDe Technology Foundation in The Netherlands) believe that their functional nanovesicle can become quite useful for nanotech studies, such as single molecule imaging, or for "bionanosensors, nanoreactors, nanomedicine, and triggered delivery."
Read: Biohybrid nanocontainers with controlled permeability...
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Friday, March 14, 2008
Scientists Develop 16-bit Parallel Molecular Nanoprocessor
One of the most intriguing possibilities of nanotechnology is in its ability to create molecular constructs that can work autonomously to perform specific tasks or functions. An artificial flagellum, powered by a nanomotor, attached to a vesicle loaded with drugs, delivering medications to a distant target, is our golden dream of the nanofuture. It is fair to say that scientists Anirban Bandyopadhyay and Somobrata Acharya from the International Center for Young Scientists, National Institute for Materials Science in Japan, are making our dreams more realistic. In the latest issue of the Proceedings of the National Academy of Sciences they are reporting a self organizing 16-bit parallel processing molecular assembly. In essence, the processor is composed of 17 molecules of duroquinone on the surface of gold, in which the central molecule controls the other 16 through hydrogen-bond channels. As a result, the system can assume a huge (416) number of positions.
From the abstract:
A machine assembly consisting of 17 identical molecules of 2,3,5,6-tetramethyl-1–4-benzoquinone (DRQ) executes 16 instructions at a time. A single DRQ is positioned at the center of a circular ring formed by 16 other DRQs, controlling their operation in parallel through hydrogen-bond channels. Each molecule is a logic machine and generates four instructions by rotating its alkyl groups. A single instruction executed by a scanning tunneling microscope tip on the central molecule can change decisions of 16 machines simultaneously, in four billion (416) ways. This parallel communication represents a significant conceptual advance relative to today's fastest processors, which execute only one instruction at a time.
Imagine a future where such a processor is a part of an in vivo nanopacemaker, siting right inside the AV node. Wow!
Abstract: A 16-bit parallel processing in a molecular assembly
More from MSNBC Cosmic Log...
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Handheld Biosensor Uses Stickly Nanotech to Capture DNA
Methods to detect the presence of specific DNA molecules have been around for a long time. However, they are slow, expensive and not particularly easy to transport. Although we have heard of particularly avid scientists carrying around PCR machines in their luggage, Samuel Afuwape of National University at San Diego thinks that an ion-selective field-effect transistor might take up a bit less room in our suitcase:
Afuwape suggests that a new type of electronic device, the ion-selective field-effect transistor (ISFET), might be integrated into a DNA biosensor. Such a sensor would be coated with thousands of known DNA sequences that could match up - hybridize - with specific DNA fragments in a given medical or environmental sample.The key to making the system work is that the ISFET can measure changes in conductivity. Constructing a sensor so that the process of DNA hybridization is coupled to a chemical reaction that generates electricity would produce discrete electronics signals. These signals would be picked up by the ISFET. The characteristic pattern of the signals would correspond to hybridization of a known DNA sequence on the sensor and so could reveal the presence of its counterpart DNA in the sample. Afuwape's mathematical work demonstrates that various known chemical reaction circuits involving DNA could be exploited in such a sensor.
"The ISFET is proving to be a powerful platform on which to design and develop selective, sensitive, and fast miniature DNA sensors," says Afuwape, "such portable DNA sensors will find broad application in medical, agriculture, environmental and bioweapons detection."
Press Release: Handheld DNA detector
Image credit: Wellcome Images: Plasmid DNA on a mineral sheeet
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Tuesday, March 11, 2008
Orthogonal Microscope for 3D Tracking of Nanoparticles
A new microscope design from scientists at the National Institute of Standards and Technology (NIST) should allow better design of all kinds of nanotech devices:
While some nanoscale fabrication techniques borrow from the lithography and solid state methods of the microelectronics industry, an equally promising approach relies on “directed self-assembly.” This capitalizes on physical properties and chemical affinities of nanoparticles in solutions to induce them to gather and arrange themselves in desired structures at desired locations. Potential products include extraordinarily sensitive chemical and biological sensor arrays, and new medical and diagnostic materials based on “quantum dots” and other nanoscale materials. But when your product is too small to be seen, monitoring the assembly process is difficult.Microscopes can help, but a microscope sees a three-dimensional fluid volume as a 2-D plane. There’s no real sense of the “up and down” movement of particles in its field of view except that they get more or less fuzzy as they move across the plane where the instrument is in focus. To date, attempts to provide a 3-D view of the movements of nanoparticles in solution largely have relied on that fuzziness. Optics theory and mathematics can estimate how far a particle is above or below the focal plane based on diffraction patterns in the fuzziness. The math, however, is extremely difficult and time consuming and the algorithms are imprecise in practice.
One alternative, NIST researchers reported at the annual meeting of the American Physical Society,* is to use geometry instead of algebra. Specifically, angled side walls of the microscopic sample well act as mirrors to reflect side views of the volume up to the microscope at the same time as the top view. (The typical sample well is 20 microns square and 15 microns deep.) The microscope sees each particle twice, one image in the horizontal plane and one in the vertical. Because the two planes have one dimension in common, it’s a simple calculation to correlate the two and figure out each particle’s 3-D path. “Basically, we reduce the problem of tracking in 3-D to the problem of tracking in 2-D twice,” explains lead author Matthew McMahon.
The 2-D problem is simpler to solve—several software techniques can calculate and track 2-D position to better than 10 nanometers. Measuring the nanoparticle motion at that fine scale—speeds, diffusion and the like—will allow researchers to calculate the forces acting on the particles and better understand the basic rules of interaction between the various components. That in turn will allow better design and control of nanoparticle assembly processes.
Full story: All Done With Mirrors: NIST Microscope Tracks Nanoparticles in 3-D...
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Thursday, February 28, 2008
World's Largest Sheet of Carbon Nanotube Material
Nanocomp Technologies, a Concord, NH company, has produced the largest blanket in the world made out of woven carbon nanotubes. So, what is it good for? The material has pretty amazing properties: stronger than steel, with a breaking strength around 150,000 PSI, efficient heat transferrer, conductor of electricity, lightweight and malleable composition, thin as paper, and more. The material could be used for things like body armor and enclosures of electronic devices, but also for a variety of medical applications, such as heating blankets, or even implantable gadget casings:
At the core of Nanocomp’s process is a breakthrough technology for continuous, high-volume output of millimeter-long, highly pure carbon nanotubes that efficiently conduct both heat and electricity. By bringing this technology to practice using proven, scalable industrial processes, Nanocomp can now produce sheets of material at contiguous sizes of tens of square feet.Nanocomp’s materials possess a unique combination of high strength-to-weight ratio, electrical and thermal conductivity, as well as flame resistance that exceeds those of many other advanced materials by orders of magnitude. The resulting material can be a valuable addition to such applications such as electromagnetic interference (EMI) shielding, electrical conductors, thermal dissipation solutions, lightning protection and advanced structural composites.
In contrast to Nanocomp’s millimeter-long nanotubes, other carbon nanotubes are short—tens of microns long — and are usually delivered in powder form. Short nanotubes have limited industrial use because they are difficult to incorporate into existing manufacturing processes and do not possess the high performance properties of long carbon nanotubes.
“Nanocomp Technologies has made the crucial growth step moving from research to production with the implementation of aggressively scaled up operations to allow production of the world’s largest sheets of carbon nanotube material,” said Peter Antoinette, president and CEO of Nanocomp. “This process forms the basis for our strategy to produce value-added CNT components from unique nanomaterials. We’re gratified at the reception our materials have received from major industrial companies. We believe today’s news and proof of our ability to scale up and deliver increasingly larger volumes will be of even greater interest to Nanocomp’s prospective customers and strategic partners.”
Mark Banash, Nanocomp’s vice president of engineering, said: “The goal of our manufacturing scale-up has been to product ultra-pure material in increasing quantities, with consistency and reliability utilizing a fully automated, process that doesn’t require a Ph.D. to operate. We’re confident that we’re going to be in a position to offer the volume, material formats and quality that players across many industrial markets need. By continually improving the economics and performance characteristics of our products, we think Nanocomp is the first company that’s going to deliver on the promise of carbon nanotube technology.”
Press release: Nanocomp Technologies Produces World's Largest Sheet of Carbon Nanotube Material...
Nature: Nano makes it big...
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Tuesday, February 26, 2008
Scientists Create Organic FET Transistor
Scientists at the National Institute of Standards and Technology have successfully built a functional field effect transistor (FET), the basic building block of computer electronics, out of organic molecules. The advantages of building computer chips out of things other than silicon are numerous, especially within specific fields like medicine. High temperatures during manufacturing and the fact that silicon chips have to be rigid are factors that make standard processors difficult to integrate into certain (pliable?) medical devices.
The essential structure consists of two electrical contacts with a channel of semiconductor between them. The researchers found that by applying a specially tailored pretreatment compound to the contacts before applying the organic semiconductor solution, they could induce the molecules in solution to self-assemble into well-ordered crystals at the contact sites.These structures grow outwards to join across the FET channel in a way that provides good electrical properties at the FET site, but further away from the treated contacts the molecules dry in a more random, helter-skelter arrangement that has dramatically poorer properties--effectively providing the needed electrical isolation for each device without any additional processing steps. The work is an example of the merging of device structure and function that may enable low cost manufacturing, and an area where organic materials have important advantages.
In addition to its potential as a commercially important manufacturing process, the authors note, this chemically engineered self-ordering of organic semiconductor molecules can be used to create test structures for fundamental studies of charge transport and other important properties of a range of organic electronic systems.
More from NSIT press release...
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Monday, February 25, 2008
Nanotube Wires Shown to Operate at Speed of Commercial Chips
As we know, there is much hope in the scientific community in the ability of carbon nanotubes to become the basic building blocks of future medical devices that will be stuffed with such technologies as organic-based computational biochips. Now scientists from Stanford University and Toshiba report using nanotubes to wire a silicon chip that turned out to operate at speeds comparable to those of commercially available processors and memory:
"This is the first time anyone has been able to show digital signals going through nanotubes at 1 gigahertz [a billion times a second]," said H.-S. Philip Wong, a professor of electrical engineering at Stanford and a co-author of the report. "There had been a lot of expectations that nanotubes could do this, but no experimental proof so far."At stake is the continuation of the