Articles from February 2015


Newly developed tiny antennas, likened to spotlights on the nanoscale, offer the potential to measure food safety, identify pollutants in the air and even quickly diagnose and treat cancer, according to the Australian scientists who created them. The new antennas are cubic in shape. They do a better job than previous spherical ones at directing an ultra-narrow beam of light where it is needed, with little or no loss due to heating and scattering, they say.

In a paper published in the Journal of Applied Physics, from AIP Publishing, Debabrata Sikdar of Monash University in Victoria, Australia, and colleagues describe these and other envisioned applications for their nanocubes in “laboratories-on-a-chip.” The cubes, composed of insulating, rather than conducting or semiconducting materials as were the spherical versions, are easier to fabricate as well as more effective, he says.

Sikdar’s paper presents analysis and simulation of 200-nanometer dielectric (nonconductive) nanoncubes placed in the path of visible and near-infrared light sources. The nanocubes are arranged in a chain, and the space between them can be adjusted to fine-tune the light beam as needed for various applications. As the separation between cubes increases, the angular width of the beam narrows and directionality improves, the researchers say.

Unidirectional nanoantennas induce directionality to any omnidirectional light emitters like microlasers, nanolasers or spasers, and even quantum dots,” Sikdar said in an interview. Spasers are similar to lasers, but employ minute oscillations of electrons rather than light. Quantum dots are tiny crystals that produce specific colors, based on their size, and are widely used in color televisions. “Analogous to nanoscale spotlights, the cubic antennas focus light with precise control over direction and beam width,” he said.

Solar Film: How To Increase The Absorption Of Sunlight

A biological structure in mammalian eyes has inspired a team headed by Silke Christiansen to design an inorganic counterpart for use in solar cells. With the help of conventional semiconductor processes, they etched micron-sized vertical funnels shoulder-to-shoulder in a silicon substrate. Using mathematical models and experiments, they tested how these kind of funnel arrays collect incident light and conduct it to the active layer of a silicon solar cell. Their result: this arrangement of funnels increases photo absorption by about 65% in a thin-film solar cell fitted with such an array and is reflected in considerably increased solar cell efficiency, among other improved parameters. This closely packed arrangement of cones has now inspired the team headed by Prof. Silke Christiansen to replicate something similar in silicon as a surface for solar cells and investigate its suitability for collecting and conducting light. Christiansen heads the Institute for Nanoarchitectures for Energy Conversion at the Helmholtz-Zentrum Berlin (HZB) and a research team at the Max Planck Institute for the Science of Light (MPL) – Germany..

solar funnelThe simulation shows how the concentration of light (red = high concentration, yellow= low concentration) rises in the funnels with declining diameter of the lower end of the funnel
We’ve shown in this work that the light funnels absorbs considerably more light than other optical architectures tested over the last while”, says Sebastian Schmitt, one of the two first authors of the publication that has appeared in journal Nature Scientific Reports.


Invisible Drum Kit To Stay On Good Terms With Neighbours

What you’re seeing is not a trick … this is an invisible drum kit. Aerodrums uses real-time motion-tracking technology to accurately translate the movements of the drummer into sounds. But unlike a traditional drum kit, this one is small enough to carry in a bag and – when used with headphones – won’t annoy the neighbours. Bright light illuminates retro-reflective markers on the drum sticks and feet, with a high speed camera tracking the motion.
A drummer himself since he was nine, co-inventor Richard Lee said complex algorithms make the Aerodrums experience realistic.
aerodrumsCLICK on the image to enjoy the video
It’s very velocity sensitive, so if you hit quiet you get very quiet sounds, if you hit loud, you hear loud sounds. It’s very responsive. It took a lot of research to get the latency as low as possible because that’s the thing that kind of breaks the illusion of ‘aerodrumming‘. If there’s any latency at all then drummers can perceive it and it doesn’t feel right“, says Richard Lee.
If you were back stage and warming up before you want out and played; you could choose those. If you were in a hotel room, you can just put your headphones on. And it’s great, it’s a great tool“, adds Professional drummer Mike Dolbear, who has been performing and teaching the drums for 35 years. Here, he tries out Aerodrums for the first time… The makers have toyed with idea of Aerodrums gloves for playing hand drums and even combining a virtual reality headset. But co-inventor Yann Morvan said their priority was making Aerodrums a viable alternative for drummers, and not a novelty.
We didn’t want Aerodrums to be a fad. We didn’t want it to be the gadget of the year and then it’s forgotten. We wanted it to be a proper musical instrument, that is introducing air drumming as a legitimate way to drum. And keeps going, keeps improving until it’s fine to air drum live, it’s fine to record using air drums because it’s a real musical instrument.”
Traditional drummers may take some convincing before they make the switch. But for those without the space, or who want to stay on good terms with their neighboursAerodrums could hit the spot.

How To Dissolve Blood Clots A Thousand Times Faster

By loading magnetic nanoparticles with drugs and dressing them in biochemical camouflage, Houston Methodist researchers say they can destroy blood clots 100 to 1,000 times faster than a commonly used clot-busting technique.

The finding, reported in Advanced Functional Materials, is based on experiments in human blood and mouse clotting models. If the drug delivery system performs similarly well in planned human clinical trials, it could mean a major step forward in the prevention of strokes, heart attacks, pulmonary embolisms, and other dire circumstances where clots — if not quickly busted — can cause severe tissue damage and death.

blood clot2
Each nanoparticle is composed of an iron oxide core (red squares) that is swathed in albumin (grey) and the anti-clotting agent tPA (green). The iron oxide cubes are about 20 nm on a side
We have designed the nanoparticles so that they trap themselves at the site of the clot, which means they can quickly deliver a burst of the commonly used clot-busting drug tPA where it is most needed,” said Paolo Decuzzi, Ph.D., the study’s co-principal investigator.

Decuzzi leads the Houston Methodist Research Institute Dept. of Translational Imaging.

3D Printer-Scanner Revolutionizes Additive Manufacturing

Nanyang Technological University’s (NTU) start-up Blacksmith Group (Singapore) today launched the world’s first compact 3D printer that can also scan items into digitised models. Named the Blacksmith Genesis, this user-friendly device allows users without much knowledge of 3D software to scan any item, then edit the digitised model on the computer and print it out in 3D. The all-in-one 3D printer and scanner whose production was financed through a crowdfunding campaign on, was unveiled at the American Association Advancement of Science (AAAS) Annual Meeting in San Jose, California.
The first batch is now ready to be shipped out in March to early adopters who supported Blacksmith Group’s crowdfunding campaign.

Housed in a black aluminium casing, the high-tech device weighing 6 kilograms features a 2-inch LCD display, Wi-Fi, an integrated SD-card reader and a USB connection for instant printing. Blacksmith Genesis uses an innovative rotary platform for its printing and scanning, unlike other commercial 3D printers. This patent-pending revolving platform allows for true 360-degrees scanning, and can print items up to 6,650 cm3 (about 6.5 litres), twice the size of those printed by other similar-sized 3D printers in the market.

With a fine resolution of 50 micrometres, the reproductions will be twice as detailed compared to other compact 3D printers. Likewise, scanning of objects with its 5 megapixel camera takes only 6 minutes, twice as fast as other 3D scanners in the market. Blacksmith Genesis is also the first to feature remote live monitoring and automatic error detection thanks to its in-built camera. This allows users to monitor and control the printing process on their smartphone from anywhere in the world through the Internet.
3D printerWith a fine resolution of 50 micrometres, the reproductions will be twice as detailed compared to other compact 3D printers. Likewise, scanning of objects with its 5 megapixel camera takes only 6 minutes, twice as fast as other 3D scanners in the market. Blacksmith Genesis is also the first to feature remote live monitoring and automatic error detection thanks to its in-built camera. This allows users to monitor and control the printing process on their smartphone from anywhere in the world through the Internet

We designed Blacksmith Genesis with the average hobbyist in mind. Most 3D printers sold on the market now are not really user-friendly as their 3D models and blueprints usually have to be designed from scratch on the computer”, said the Blacksmith team. “However, with our device, 3D printing will be fuss-free as users won’t need to design an original work from scratch as they can just use our Blacksmith Sorcerer 3D software. By scanning any physical item, they can immediately copy and print the item or use the digitised object as a base to form their own 3D object.”

The device is the brainchild of Blacksmith Group’s founders, NTU engineering graduate Dr Alex Pui Tze Sian and Mr Fang Kok Boon. Mr Fang, CEO of Blacksmith Group, said their aim is to make 3D printing easy and accessible to the average consumers.

How To Boost Electric Vehicle Batteries

Researchers from the Professor Mihri Ozkan lab at the University of California, Riverside’s Bourns College of Engineering have developed a novel paper-like material for lithium-ion batteries. It has the potential to boost by several times the specific energy, or amount of energy that can be delivered per unit weight of the battery.
This paper-like material is composed of sponge-like silicon nanofibers more than 100 times thinner than human hair. It could be used in batteries for electric vehicles and personal electronics.

electric carThe problem with silicon is that is suffers from significant volume expansion, which can quickly degrade the battery. The silicon nanofiber structure created in the Ozkan’s labs circumvents this issue and allows the battery to be cycled hundreds of times without significant degradation. This technology also solves a problem that has plagued free-standing, or binderless, electrodes for years: scalability. Free-standing materials grown using chemical vapor deposition, such as carbon nanotubes or silicon nanowires, can only be produced in very small quantities (micrograms). However, the team was able to produce several grams of silicon nanofibers at a time even at the lab scale.

The nanofibers were produced using a technique known as electrospinning, whereby 20,000 to 40,000 volts are applied between a rotating drum and a nozzle, which emits a solution composed mainly of tetraethyl orthosilicate (TEOS), a chemical compound frequently used in the semiconductor industry. The nanofibers are then exposed to magnesium vapor to produce the sponge-like silicon fiber structure.

The findings were just published in the journal Nature Scientific Reports.

NanoDrones Destroy Fat In Arteries

Nanometer-sized “drones” will deliver a special type of healing molecule to fat deposits in arteries. This is new approach to prevent heart attacks caused by atherosclerosis, according to a study in pre-clinical models by scientists at Brigham and Women’s Hospital (BWH) and Columbia University Medical Center.

Although current treatments have reduced the number of deaths from atherosclerosis-related disease, atherosclerosis remains a dangerous health problem: Atherosclerosis of the coronary arteries is the #1 killer of women and men in the U.S., resulting in one out of every four deaths. In the study, targeted biodegradable nanodrones’ that delivered a special type of drug that promotes healing (‘resolution‘) successfully restructured atherosclerotic plaques in mice to make them more stable. This remodeling of the plaque environment would be predicted in humans to block plaque rupture and thrombosis and thereby prevent heart attacks and strokes.
nanodronesNanometer-sized ‘drones’ that deliver a special type of healing molecule to fat deposits in arteries could become a new way to prevent heart attacks caused by atherosclerosis
This is the first example of a targeted nanoparticle technology that reduces atherosclerosis in an animal model,” said co-senior author Omid Farokhzad, MD, associate professor and director of the Laboratory of Nanomedicine and Biomaterials at BWH and Harvard Medical School (HMS). “Years of research and collaboration have culminated in our ability to use nanotechnology to resolve inflammation, remodel and stabilize plaques in a model of advanced atherosclerosis.”

These findings are published in the February 18th online issue of Science Translational Medicine.

Gold Nanotubes Attack Cancer Cells

Scientists have shown that gold nanotubes have many applications in fighting cancer: internal nanoprobes for high-resolution imaging; drug delivery vehicles; and agents for destroying cancer cells.
Study lead author Dr Sunjie Ye, who is based in both the School of Physics and Astronomy and the Leeds Institute for Biomedical and Clinical Sciences at the University of Leeds, said: “High recurrence rates of tumours after surgical removal remain a formidable challenge in cancer therapy. Chemo- or radiotherapy is often given following surgery to prevent this, but these treatments cause serious side effects. Gold nanotubes – that is, gold nanoparticles with tubular structures that resemble tiny drinking straws – have the potential to enhance the efficacy of these conventional treatments by integrating diagnosis and therapy in one single system.”

The researchers say that a new technique to control the length of nanotubes underpins the research. By controlling the length, the researchers were able to produce gold nanotubes with the right dimensions to absorb a type of light called ‘near infrared’.

gold nanotubes
Human tissue is transparent for certain frequencies of light – in the red/infrared region. This is why parts of your hand appear red when a torch is shone through it”, said the Professor Steve Evans, from the School of Physics and Astronomy at the University of Leeds and who is the study’s corresponding author. When the gold nanotubes travel through the body, if light of the right frequency is shone on them they absorb the light. This light energy is converted to heat, rather like the warmth generated by the Sun on skin. Using a pulsed laser beam, we were able to rapidly raise the temperature in the vicinity of the nanotubes so that it was high enough to destroy cancer cells.”

The study, published in the journal Advanced Functional Materials, details the first successful demonstration of the biomedical use of gold nanotubes in a mouse model of human cancer.


Silicon Valley Made in Sweden

A production facility for start-ups in the field of nanotechnology may be built in the Science Village in Lund, a world-class research and innovation village that is also home to ESS, the European Spallation Source.
The project originates from the successful research into nanowires at Lund University, which has resulted in nanotechnology companies like Glo AB and Sol Voltaics AB. Glo was forced to move to Silicon Valley, however, to launch large-scale mass production.

The infrastructure would be intended for companies and researchers in the whole of Sweden who want to develop products with industry standards without needing to invest in expensive equipment themselves.
nano industry
With this new facility, we want to create the conditions to enable new companies to develop from the R&D phase to full production, without needing to leave Sweden,” says Lars Samuelson, Professor of Nanophysics at Lund University.

Samuelson sees more business opportunities for nanowires. In addition to Glo’s light-emitting diodes and Sol Voltaicssolar cells, Lars Samuelson believes there is potential for new companies focused on applications within electronics, UV light-emitting diodes and biomedicine.

Alongside this project, Lund University is working to extend the Lund Nano Lab which is a pure research laboratory for research on nanowires. This is run by Lund University, whereas the industrial facility is a project outside the University. Together, these two initiatives constitute a way of generating the whole value chain from research to market.


How To Produce Graphene Massively

With properties that promise faster computers, better sensors and much more, graphene has been dubbed the ‘miracle material’. But progress in producing it on an industrial scale without compromising its properties has proved elusive. University of Groningen (Netherlands) scientists may now have made a breakthrough.

Graphene is a special material with crystals that are just one atom thick. Electrons pass through it with hardly any resistance at all, and despite being very flexible, it is stronger than any metal. The discoverers of graphene, Andre Geim and Konstantin Novoselov, famously made it by peeling graphite with Scotch tape until they managed to isolate a single atomic layer: graphene. It won them the 2010 Nobel Prize in Physics.

The challenge is to find a substrate that not only preserves the properties of graphene, but also enables scalable production’, says Stefano Gottardi, PhD student at the University of Groningen Zernike Institute for Advanced Materials. A good candidate is chemical vapour deposition. Here heat is used to vaporize a carbon precursor like methane, which then reacts with a catalytically active substrate to form graphene on its surface. A transition metal is normally used as the substrate. However, not only does the transition metal act as a support, but it also tends to interact with the graphene and modify – or even deteriorate – its outstanding properties. To restore these properties after growth on the metal, the graphene has to be transferred to a non-interacting substrate. Gottardi and his colleagues have managed to successfully grow graphene on copper oxide. This achievement together with an in-depth characterization of graphene’s properties will be published in Nano Letters.


How To Read DNA Sequences In One Second

Despite having a diameter tens of thousands of times smaller than a human hair, nanopores could be the next big thing in DNA sequencing. By zipping DNA molecules through these tiny holes, scientists hope to one day read off genetic sequences in the blink of an eye. Now, researchers from Brown University have taken the potential of nanopore technology one step further. They have combined a nanopore with a tiny cage capable of trapping and holding a single DNA strand after it has been pulled through the pore. While caged, biochemical experiments can be performed on the strand, which can then be zipped back through the nanopore to look at how the strand has changed.

Nanopore1How the nanoscale cage works? An electrical field draws a strand of DNA in by the smaller hole, bottom, but the curled DNA cannot exit through the larger hole, top. After experimental procedures, a reversed electrical field draws the DNA strand back out of the lower hole, allowing before and after comparison

We see this as a very interesting enabling technique,” said Derek Stein, associate professor of physics and engineering at Brown, who helped develop the technology with his graduate students. “It allows you for the first time to look at the same molecule before and after any kind of chemical reaction that may have taken place.”

A paper describing the device is published in Nature Communications.


Li-Ion Batteries Mimick Shells To Last Longer

Scientists are using biology to improve the properties of lithium ion batteries. Researchers at the University of Maryland, Baltimore County (UMBC) have isolated a peptide, a type of biological molecule, which binds strongly to lithium manganese nickel oxide (LMNO), a material that can be used to make the cathode in high performance batteries. The peptide can latch onto nanosized particles of LMNO and connect them to conductive components of a battery electrode, improving the potential power and stability of the electrode.

Biology provides several tools for us to solve important problems,” said Evgenia Barannikova, a graduate student at UMBC. Barannikova works in the lab of Mark Allen and studies how biological molecules in general can improve the properties of inorganic materials in batteries.

Biology provides several tools for us to solve important problems,” said Evgenia Barannikova, a graduate student at UMBC. Barannikova works in the lab of Mark Allen and studies how biological molecules in general can improve the properties of inorganic materials in batteries.
By providing a new nanoscale architecture for lithium-ion batteries, the researchers say that the approach could improve the power and cycling stability of lithium-ion batteries.
The researchers will present their results at the 59th annual meeting of the Biophysical Society, held Feb. 7-11 in Baltimore, Maryland.