Friday, July 31, 2009

One of the first things that come to mind when thinking about Harry Potter and his cloak is … invisibility. Now researchers in Spain have developed a device that makes objects invisible under a certain kind of light. Called 'dc metamaterial', the device brings the inside of the magnetic field down to zero but does not change the exterior field.

Staying in the realm of fantasy and science fiction, ‘transparent aluminium’ previously only existed in the movie Star Trek IV, but the real material is an exotic new state of matter with implications for planetary science and nuclear fusion. Oxford scientists have created a transparent form of aluminium by bombarding the metal with the world’s most powerful soft X-ray laser.

By studying gold nanoparticles with highly uniform sizes and shapes, scientists now understand how they lose energy, a key step towards producing nanoscale detectors for weighing any single atom. Such ultrasensitive measurements could ultimately be used in areas such as medical research and diagnostics, enabling the detection of minuscule disease-causing agents such as viruses and prions at the single molecule level.

An interesting development in nanoparticle synthesis is the concept of an 'evolutionary tree'. The tree not only displays the relationship between different shapes, but also offers designing principles for producing more complex shapes by crossing over different pathways during nanoparticle growth.

evolutionary tree for nanoparticles

Driven by the vision of our society one day being basically self-propelled, a team of University of Houston scientists has set out to both amplify and provoke that potential in materials known as piezoelectrics, which naturally produce electricity when literally subjected to strain. The goal is to use piezoelectrics to create nanodevices that can power electronics, such as cell phones, MP3 players and even biomedical implants.

Researchers are working on ways to make lasers smaller and smaller. This ultimately opens up possibilities for using nanoscale lasers to significantly improve the performance of computers and speed up Internet access.

Researchers at UC Riverside report the first direct observation and controlled creation of one- and two-dimensional ripples in graphene sheets. This study is first to experimentally quantify thermal contraction of graphene. Using simple thermal manipulation, the researchers produced the ripples, and controlled their orientation, wavelength and amplitude. Another research team provides two new reasons for using graphene ribbons as interconnects in future computer chips. They found that in widths as narrow as 16 nanometers, graphene has a current carrying capacity approximately a thousand times greater than copper – while providing improved thermal conductivity.

Nanoparticles are being developed to perform a wide range of medical uses – imaging tumors, carrying drugs, delivering pulses of heat. Rather than settling for just one of these, researchers at the University of Washington have combined two nanoparticles in one tiny package. The result is the first structure that creates a multipurpose nanotechnology tool for medical imaging and therapy.

In the classic fairy tale, “The Emperor’s New Clothes,” Hans Christian Andersen uses the eyes of a child to challenge conventional wisdom and help others to see more clearly. In similar fashion, researchers at the University of Illinois have now revealed the naked truth about a classic bell-shaped curve used to describe the motion of a liquid as it diffuses through another material ('Brownian motion').

A team of Japanese scientists have developed a biodegradable nanosheet of only about 20 nanometers thickness that could replace surgical stitches and result in scar-free wound healing. In experiments they found that the sealing operation repaired the incision completely without scars and tissue adhesion. This approach would constitute an ideal candidate for an alternative to conventional suture/ligation procedures, from the perspective not only of a minimally invasive surgical technique but also reduction of operation times.

Friday, July 24, 2009

Lots of nanomedicine news this week:

In future therapies, synthetic nanoparticles may well be able to ferry medicines and even genes to targets inside the body. These nanovehicles can now be directly tested and optimized using a highly sensitive microscopic method that can trace single particles all the way into a cell. In related news, physicists at New York University have developed a technique to record three-dimensional movies of microscopic systems, such as biological molecules, through holographic video. The work has potential to improve medical diagnostics and drug discovery.

Surgical removal of a tissue sample is now the standard for diagnosing cancer. Such procedures, known as biopsies, are accurate but offer only a snapshot of the tumor at a single moment in time. Monitoring a tumor for weeks or months after the biopsy and tracking its growth and how it responds to treatment would be much more valuable, says MIT professor Michael J. Cima, who has developed the first implantable cancer monitoring device that can do just that. One of the earliest events that changes a normal cell into a malignant one is known as deoxyribonucleic acid (DNA) hypermethylation, a biochemical alteration that inactivates critical tumor-suppressor genes. Other progress in early identification of cancer cells was reported at Johns Hopkins University: A team there has developed a quantum dot-based method that can quantify DNA methylation in premalignant cells harvested from human patients.

Twinkle, twinkle, little star: A new approach to biomedical imaging with magnetically responsive gold nanostars has been reported by Purdue University researchers who have created magnetically responsive gold nanostars that may offer a new approach to biomedical imaging. The nanostars gyrate when exposed to a rotating magnetic field and can scatter light to produce a pulsating or "twinkling" effect. This twinkling allows them to stand out more clearly from noisy backgrounds like those found in biological tissue.

An interdisciplinary team of scientists led by Princeton engineers has been awarded a $3 million grant to study how fuel additives made of nanocatalysts can help supersonic jets fly faster and make diesel engines cleaner and more efficient.

Nanoscale mass spectrometer: using a carbon nanotube, Caltech researchers have developed a technique to determine the mass of a single molecule, in real time. In a not too different set-up, a Dutch team has succeeded in measuring the influence of a single electron on a vibrating carbon nanotube.

Staying with carbon nanotubes, the fundamental issue of large-scale carbon nanotube device fabrication remains the biggest challenge for effective commercialization of CNT-based nanoelectronic devices. A research team in Israel reports a new method to to achieve the integration of carbon nanotubes into micro-fabricated devices.

The first artificial graphene has been created at the NEST laboratory of the Italian Institute for the Physics of Matter (INFM-CNR) in Pisa. It is sculpted on the surface of a gallium-arsenide semiconductor, to which it grants the extraordinary properties of the original graphene.

And some nanoelectronics: A Rice University lab is manipulating molecules that might just be the ticket to extending Moore's Law, the theory that dictates the number of transistors that can be placed on an integrated circuit doubles about every two years.

international coalitions of NGOs, the European Environmental Bureau and the International POPs Elimination Network (IPEN) Nanotechnology Working Group, have challenged industry claims about the potential environmental benefits provided by nanotechnology products: Nanotechnologies are presented as providing unprecedented technological solutions to many environmental problems including climate change, pollution and clean drinking water. Proponents claim that it enables economic growth through better products and new markets while dramatically reducing our ecological footprint. However there is emerging evidence these claims do not provide the whole picture, with serious environmental risks and costs being trivialized or ignored.

Friday, July 17, 2009

This week in nanotechnology July 11-17, 2009

Lots of news in nanoelectronics and nanophotonics this week: Light-based computing took another step forward with the discovery by Yale scientists of a "repulsive" light force that can be used to control components on silicon microchips. Researchers had theorized the existence of both the attractive and repulsive forces since 2005, but the latter had remained unproven until now. These novel repulsive and attractive nanophotonic forces were also reported by a European team.

Computers with no need of cooling? They haven't come into existence yet. However, physicists in Germany are paving the way for them: they demonstrate a semiconductor that transmits electric current without heating up in the process.

Capturing electrons in action – scientists at RIKEN in Japan have developed a way to measure the wavelike properties of ultrafast (attosecond) light pulses—an important step toward being able to probe the dynamics of electrons, atoms and molecules.

Relieving some concerns that nanotechnology manufacturing might be quite a 'dirty' industrial process, Singapore's Institute for Bioengineering and Nanotechnology (IBN) has discovered a new environmentally friendly method to synthesize a wide variety of nanoparticles inexpensively.

Moving on to green energy – this week a group of 20 large industrial companies, banks and insurance companies met in Germany to kick of project Desertec that, if realized, will cost 400-500 billion euros ($550-700 bn) and deliver its first energy in about 10 years. The basic idea is to install a huge network of nanotechnology-enabled concentrating solar-thermal power plants in the Sahara desert and build a network of High-Voltage Direct Current (HVDC) transmission lines to carry the electricity to Europe.

Empa in Switzerland has published a brief summary of the main conclusions reached at its third NanoConvention event held last week in Zürich. The aim of the NanoConvention is to establish nanotechnology as a secure and safe motor of innovation for the Swiss economy and society.

NanoTecNexus and the University of California, San Diego NanoTumor Center (NTC) have received the 2009 Bronze Telly Award for the production of a video on approaches to fighting cancer using nanotechnology:

And finally, staying with videos, the American Chemical Society announces its second nanotechnology video contest after the wildly successful winner of the first contest clocked almost half a million YouTube views:

Friday, July 10, 2009

This week in nanotechnology July 4-10, 2009

Computer simulations shed light on nanosized minerals. The red and blue images appear ghostly, like a fleeting glimpse of something that’s never been seen before – which is true. Using computer simulations, Berkeley Lab scientists have developed the first predicted images of water molecules surrounding a nanoparticle, in this case an iron-oxide mineral called hematite.

In nanoelectronics, the use of molecules as elements in electronic circuits shows great potential. One of the central challenges up until now has been that most molecules only start to conduct once a large voltage has been applied. An international research team has shown that molecules containing an odd number of electrons are much more conductive at low bias voltages.

On to new findings in improving solar panel efficiency. In 1907 German physicist Gustav Mie realized that tiny metal particles in stained glass scattered light in ways that produced beautiful colors. Now, a related interplay between light and matter explains why incredibly thin nanowires made of semiconductors like germanium may prove to be effective components for solar cells. Combining Mie's work with more recent theory, the Stanford team has discerned how to tune and improve the light absorption efficiency of the wires. Over at the Berkeley Lab, researchers have demonstrated a way to fabricate efficient solar cells from low-cost and flexible materials. The new design grows optically active semiconductors in arrays of nanoscale pillars, each a single crystal, with dimensions measured in nanometers

In nanomedicine, a study of human colon, pancreatic and lung cells is the first to report that cancer cells and their non-cancerous cell neighbors, although quite different under the microscope, share very similar structural abnormalities on the nanoscale level. The most striking findings were that these nanoscale alterations occurred at some distance from the tumor and, importantly, could be identified by assessing more easily accessible tissue, such as the cheek for lung cancer detection.

Researchers in Switzerland have now demonstrated novel cell biology applications using hollow force-controlled AFM cantilevers – a new device they have called FluidFM. This novel device combines AFM and nanofluidics for single cell applications.

Nanotoxicology studies on aquatic ecosystems have been scarce – although everything winds up in the water eventually. Now a team of Canadian scientists and engineers, led by the University of Alberta and the National Research Council of Canada, will collaborate on a $3.39 million, three-year study to assess the potential effects of nanoparticles in specific water environments.

Speaking about possible nanotechnology risks, there still is a lot we don't know yet about the environmental, health and safety impact of nanomaterials, but at least scientists are making progress in identifying the gaps – the 'known unknowns' as they call it.

Purification of carbon nanotubes still is a major headache for CNT producers. A team of researchers from DuPont and Lehigh University says it has developed a DNA-based method that sorts and separates specific types of CNTs from a mixture.

Not really nanotechnology but still cool stuff: Physicists have overcome a major hurdle in quantum computer development, having devised a viable way to manipulate a single "bit" in a quantum processor without disturbing the information stored in its neighbors. The approach, which makes novel use of polarized light to create effective magnetic fields, could bring the long-sought computers a step closer to reality.

And finally, for all you Harry Potter fans, a new metamaterial brings us closer to the dream of invisibility. A group of researchers in Spain have designed a device, called a dc metamaterial, which makes objects invisible under certain light by making the inside of the magnetic field zero but not altering the exterior field. The device, which up to date has only been studied in theoretical works, thus acts as an invisibility cloak, making the object completely undetectable to these waves.

Friday, July 3, 2009

This week in nanotechnology June 27 - July 3, 2009

An international team of researchers has modified chlorophyll from an alga so that it resembles the extremely efficient light antennae of bacteria. The team was then able to determine the structure of these light antennae. This is the first step to converting sunlight into energy using an artificial leaf.

Scientists have been trying for some time to find ways to produce integrated circuits that operate on the basis of photons instead of electrons. The reason is that photons do not only generate much less heat than electrons, but they also enable considerably higher data transfer rates. Researchers in Switzerland have now made a big step in this direction by successfully creating an optical transistor with a single molecule.

A tiny grid pattern has led materials scientists to an unexpected finding – the surprisingly strong and long-range effects of certain electromagnetic nanostructures used in data storage. This may add new scientific challenges to the design and manufacture of future ultra-high density data storage devices.

Finding a way to observe and record the behavior of matter at the molecular level has long been one of the holy grails among physicists. That ability could open the door to a wide range of applications in ultrafast electron microscopy used in a large array of scientific, medical and technological fields. Now, a team at the University of Nebraska-Lincoln has figured out a possible way to do that.

It's not just the material and devices that advances nanotechnologies. A new statistical analysis technique that identifies and removes systematic bias, noise and equipment-based artifacts from experimental data could lead to more precise and reliable measurement of nanomaterials and nanostructures likely to have future industrial applications.

In nanomedicine, researchers have demonstrated a novel ROS-sensitive gold nanoprobe. Environmental and behavioral factors such as excessive alcohol consumption, exposure to toxins and drugs, smoking and lack of sleep, may lead the body to produce superoxide radicals known as reactive oxygen species (ROS) that could cause cell damage through oxidation. Oxidative stress from ROS is implicated in aging and most diseases including cancer, heart disease, liver fibrosis, neurodegenerative diseases, autoimmune disorders.

More nanomedicine applications: Imagine being able to spray a compound fracture with tiny capsules that deliver a drug to bolster the immune system, stopping infection before it starts. This technology might be around the corner. A research team has developed a drug-delivery technology involving microcapsules – and a second technique, nanocoating – that have been shown to work in animal studies.

Hate your silver tooth fillings but are not happy with shorter-lived white ceramic ones? One researcher hopes a new nanotechnology technique will extend the white fillings' longevity.

How can you weigh a single atom? European researchers have built an exquisite new device with carbon nanotubes that can do just that. It may ultimately allow scientists to study the progress of chemical reactions, molecule by molecule.

Finally, not really nanotechnology but still pretty cool: A team led by Yale University researchers has created the first rudimentary solid-state quantum processor, taking another step toward the ultimate dream of building a quantum computer.