Tiny camera lens may help link quantum computers to network

Kai Wang holding a sample that has multiple metasurface camera lenses.

Credit: Lannon Harley, ANU

An international team of researchers led by The Australian National University (ANU) has invented a tiny camera lens, which may lead to a device that links quantum computers to an optical fibre network.

Quantum computers promise a new era in ultra-secure networks, artificial intelligence and therapeutic drugs, and will be able to solve certain problems much faster than today’s computers.

The unconventional lens, which is 100 times thinner than a human hair, could enable a fast and reliable transfer of quantum information from the new-age computers to a network, once these technologies are fully realised.

The device is made of a silicon film with millions of nano-structures forming a metasurface, which can control light with functionalities outperforming traditional systems.

Associate Professor Andrey Sukhorukov said the metasurface camera lens was highly transparent, thereby enabling efficient transmission and detection of information encoded in quantum light.

“It is the first of its kind to image several quantum particles of light at once, enabling the observation of their spooky behaviour with ultra-sensitive cameras,” said Associate Professor Sukhorukov, who led the research with a team of scientists at the Nonlinear Physics Centre of the ANU Research School of Physics and Engineering.

Kai Wang, a PhD scholar at the Nonlinear Physics Centre who worked on all aspects of the project, said one challenge was making portable quantum technologies.

“Our device offers a compact, integrated and stable solution for manipulating quantum light. It is fabricated with a similar kind of manufacturing technique used by Intel and NVIDIA for computer chips.” he said.

The research was conducted at the Nonlinear Physics Centre laboratories, where staff and postgraduate scholars developed and trialled the metasurface camera lens in collaboration with researchers at the Oak Ridge National Laboratory in the United States and the National Central University in Taiwan.

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Story Source:

Materials provided by Australian National University. Note: Content may be edited for style and length.

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Journal Reference:

1. Kai Wang, James G. Titchener, Sergey S. Kruk, Lei Xu, Hung-Pin Chung, Matthew Parry, Ivan I. Kravchenko, Yen-Hung Chen, Alexander S. Solntsev, Yuri S. Kivshar, Dragomir N. Neshev, Andrey A. Sukhorukov. Quantum metasurface for multiphoton interference and state reconstruction. Science, 2018; 361 (6407): 1104-1108 DOI: http://dx.doi.org/10.1126/science.aat8196

Rapid Nano-filter for clean water: Australian researchers design a rapid nano-filter that cleans dirty water 100X faster than current technology

The new technology can filter drinking water 100 times faster than current tech. Credit: Free stock photo 

Australian researchers have designed a rapid nano-filter that can clean dirty water over 100 times faster than current technology.

Simple to make and simple to scale up, the technology harnesses naturally occurring nano-structures that grow on liquid metals.

The RMIT University and University of New South Wales (UNSW) researchers behind the innovation have shown it can filter both heavy metals and oils from water at extraordinary speed.

RMIT researcher Dr. Ali Zavabeti said water contamination remains a significant challenge globally—1 in 9 people have no clean water close to home.

“Heavy metal contamination causes serious health problems and children are particularly vulnerable,” Zavabeti said.

“Our new nano-filter is sustainable, environmentally-friendly, scalable and low cost.

“We’ve shown it works to remove lead and oil from water but we also know it has potential to target other common contaminants.

“Previous research has already shown the materials we used are effective in absorbing contaminants like mercury, sulfates and phosphates.

“With further development and commercial support, this new nano-filter could be a cheap and ultra-fast solution to the problem of dirty water.”

A liquid metal droplet with flakes of aluminium oxide compounds grown on its surface. Each 0.03mm flake is made up of about 20,000 nano-sheets stacked together. Credit: RMIT University

The liquid metal chemistry process developed by the researchers has potential applications across a range of industries including electronics, membranes, optics and catalysis.

“The technique is potentially of significant industrial value, since it can be readily upscaled, the liquid metal can be reused, and the process requires only short reaction times and low temperatures,” Zavabeti said.

Project leader Professor Kourosh Kalantar-zadeh, Honorary Professor at RMIT, Australian Research Council Laureate Fellow and Professor of Chemical Engineering at UNSW, said the liquid metal chemistry used in the process enabled differently shaped nano-structures to be grown, either as the atomically thin sheets used for the nano-filter or as nano-fibrous structures.

“Growing these materials conventionally is power intensive, requires high temperatures, extensive processing times and uses toxic metals. Liquid metal chemistry avoids all these issues so it’s an outstanding alternative.”

How it works

The groundbreaking technology is sustainable, environmentally-friendly, scalable and low-cost.

The researchers created an alloy by combining gallium-based liquid metals with aluminium.

When this alloy is exposed to water, nano-thin sheets of aluminium oxide compounds grow naturally on the surface.

These atomically thin layers—100,000 times thinner than a human hair—restack in a wrinkled fashion, making them highly porous.

Microscope image of nano-sheets, magnified over 11,900 times. Credit: RMIT University

This enables water to pass through rapidly while the aluminium oxide compounds absorbs the contaminants.

Experiments showed the nano-filter made of stacked atomically thin sheets was efficient at removing lead from water that had been contaminated at over 13 times safe drinking levels, and was highly effective in separating oil from water.

The process generates no waste and requires just aluminium and water, with the liquid metals reused for each new batch of nano-structures.

The method developed by the researchers can be used to grow nano-structured materials as ultra-thin sheets and also as nano-fibres.

These different shapes have different characteristics—the ultra-thin sheets used in the nano-filter experiments have high mechanical stiffness, while the nano-fibres are highly translucent.

The ability to grow materials with different characteristics offers opportunities to tailor the shapes to enhance their different properties for applications in electronics, membranes, optics and catalysis.

The research is funded by the Australian Research Council Centre for Future Low-Energy Electronics Technologies (FLEET).

The findings are published in the journal Advanced Functional Materials.

 Explore further: Liquid metal discovery ushers in new wave of chemistry and electronics

More information: Advanced Functional Materials (2018). DOI: 10.1002/adfm.201804057

Journal reference: Advanced Functional Materials  

Provided by: RMIT University

 

MIT: Advanced thin-film technique could deliver long-lasting medication ~ Potential for Certain Types of Cancer Treatment

MIT professor Paula Hammond (right) and Bryan Hsu PhD’ 14 have developed a nanoscale film that can be used to deliver medication, either directly through injections, or by coating implantable medical devices. Photo: Dominick Reuter

Nanoscale, biodegradable drug-delivery method could provide a year or more of steady doses.

About one in four older adults suffers from chronic pain. Many of those people take medication, usually as pills. But this is not an ideal way of treating pain: Patients must take medicine frequently, and can suffer side effects, since the contents of pills spread through the bloodstream to the whole body.

Now researchers at MIT have refined a technique that could enable pain medication and other drugs to be released directly to specific parts of the body — and in steady doses over a period of up to 14 months.  The method uses biodegradable, nanoscale “thin films” laden with drug molecules that are absorbed into the body in an incremental process.

“It’s been hard to develop something that releases [medication] for more than a couple of months,” says Paula Hammond, the David H. Koch Professor in Engineering at MIT, and a co-author of a new paper on the advance. “Now we’re looking at a way of creating an extremely thin film or coating that’s very dense with a drug, and yet releases at a constant rate for very long time periods.”

In the paper, published today in the Proceedings of the National Academy of Sciences, the researchers describe the method used in the new drug-delivery system, which significantly exceeds the release duration achieved by most commercial controlled-release biodegradable films.

“You can potentially implant it and release the drug for more than a year without having to go in and do anything about it,” says Bryan Hsu PhD ’14, who helped develop the project as a doctoral student in Hammond’s lab. “You don’t have to go recover it. Normally to get long-term drug release, you need a reservoir or device, something that can hold back the drug. And it’s typically nondegradable. It will release slowly, but it will either sit there and you have this foreign object retained in the body, or you have to go recover it.”

Layer by layer

The paper was co-authored by Hsu, Myoung-Hwan Park of Shamyook University in South Korea, Samantha Hagerman ’14, and Hammond, whose lab is in the Koch Institute for Integrative Cancer Research at MIT.

The research project tackles a difficult problem in localized drug delivery: Any biodegradable mechanism intended to release a drug over a long time period must be sturdy enough to limit hydrolysis, a process by which the body’s water breaks down the bonds in a drug molecule. If too much hydrolysis occurs too quickly, the drug will not remain intact for long periods in the body. Yet the drug-release mechanism needs to be designed such that a drug molecule does, in fact, decompose in steady increments.

To address this, the researchers developed what they call a “layer-by-layer” technique, in which drug molecules are effectively attached to layers of thin-film coating. In this specific case, the researchers used diclofenac, a nonsteroidal anti-inflammatory drug that is often prescribed for osteoarthritis and other pain or inflammatory conditions. They then bound it to thin layers of poly-L-glutamatic acid, which consists of an amino acid the body reabsorbs, and two other organic compounds. The film can be applied onto degradable nanoparticles for injection into local sites or used to coat permanent devices, such as orthopedic implants.

In tests, the research team found that the diclofenac was steadily released over 14 months. Because the effectiveness of pain medication is subjective, they evaluated the efficacy of the method by seeing how well the diclofenac blocked the activity of cyclooxygenase (COX), an enzyme central to inflammation in the body.

“We found that it remains active after being released,” Hsu says, meaning that the new method does not damage the efficacy of the drug. Or, as the paper notes, the layer-by-layer method produced “substantial COX inhibition at a similar level” to pills.

The method also allows the researchers to adjust the quantity of the drug being delivered, essentially by adding more layers of the ultrathin coating.

A viable strategy for many drugs

Hammond and Hsu note that the technique could be used for other kinds of medication; an illness such as tuberculosis, for instance, requires at least six months of drug therapy.

“It’s not only viable for diclofenac,” Hsu says. “This strategy can be applied to a number of drugs.”

Indeed, other researchers who have looked at the paper say the potential medical versatility of the thin-film technique is of considerable interest.

“I find it really intriguing because it’s broadly applicable to a lot of systems,” says Kathryn Uhrich, a professor in the Department of Chemistry and Chemical Biology at Rutgers University, adding that the research is “really a nice piece of work.”

To be sure, in each case, researchers will have to figure out how best to bind the drug molecule in question to a biodegradable thin-film coating. The next steps for the researchers include studies to optimize these properties in different bodily environments and more tests, perhaps with medications for both chronic pain and inflammation.

A major motivation for the work, Hammond notes, is “the whole idea that we might be able to design something using these kinds of approaches that could create an [easier] lifestyle” for people with chronic pain and inflammation.

Hsu and Hammond were involved in all aspects of the project and wrote the paper, while Hagerman and Park helped perform the research, and Park helped analyze the data.

The research described in the paper was supported by funding from the U.S. Army and the U.S. Air Force.

NREL Wins Award for Isothermal Battery Calorimeters – Measuring Battery Heat Levels and Energy Efficiency with 98% Accuracy – Video

” …. The IBCs can determine heat levels and battery energy efficiency with 98% accuracy and provide precise measurements through complete thermal isolation.”

NREL’s R&D 100 Award-winning Isothermal Battery Calorimeters (IBCs) are the only calorimeters in the world capable of providing the precise thermal measurements needed for safer, longer-lasting, and more cost-effective electric-drive vehicle (EDV) batteries. In order for EDVs hybrids (HEVs), plug-in hybrids (PHEVs), and all-electric vehicles (EVs) to realize ultimate market penetration, their batteries need to operate at maximum efficiency, performing at optimal temperatures in a wide range of driving conditions and climates, and through numerous charging cycles.

Cutaway showing battery in the test chamber, heat flux gauges, isothermal fluid surrounding the test chamber, and outside container with insulation holding the bath fluid and the test chamber. Image: Courtesy of NETZSCH

 

NREL’s IBCs make it possible to accurately measure the heat generated by electric-drive vehicle batteries, analyze the effects of temperature on battery systems, and pinpoint ways to manage temperatures for the best performance and maximum life. Three models, the IBC 284, the Module IBC, and the Large-Volume IBC, make it possible to test energy devices at a full range of scales.

The World’s Most Precise Battery Calorimeters

Development of precisely calibrated battery systems relies on accurate measurements of heat generated by battery modules during the full range of charge/discharge cycles, as well as determination of whether the heat was generated electrochemically or resistively. The IBCs can determine heat levels and battery energy efficiency with 98% accuracy and provide precise measurements through complete thermal isolation. These are the first calorimeters designed to analyze heat loads generated by complete battery systems.

This video describes NREL’s R&D 100 Award-winning Isothermal Battery Calorimeters, the only calorimeters in the world capable of providing the precise thermal measurements needed for safer, longer-lasting, and more cost-effective electric-drive vehicle batteries.

Calorimeter Specifications

Specifications	IBC 284 (Cell)	Module IBC	Large-Volume IBC (Pack)
Maximum Voltage (Volts)	50	500	600
Sustained Maximum Current (Amps)	250	250	450
Excursion Currents (Amps)	300	300	1,000
Volume (liters)	9.4	14.7	96
Maximum Dimensions (cm)	20.3 x 20.3 x 15.2	35 x 21 x 20	60 x 40 x 40
Operating Temperature (C)	-30 to 60	-30 to 60	-40 to 100
Maximum Constant Heat Generation	50	150	4,000

Working with Industry to Fine-Tune Energy Storage Designs

The IBCs’ capabilities make it possible for battery developers to predict thermal performance before installing batteries in vehicles. Manufacturers use these metrics to compare battery performance to industry averages, troubleshoot thermal issues, and fine-tune designs.

NREL in partnership with NETSCH Instrument North America and with support from the U.S. Department of Energy is using IBCs to help industry design better thermal management systems for EDV battery cells, modules, and packs. The U.S. Advanced Battery Consortium (USABC) and its partners rely on NREL for precise measurement of energy storage devices’ heat generation and efficiency under different states of charge, power profiles, and temperatures.

Documentary: The Quest for the Super Battery: 2017 ~ Video

 

*** Note To Readers: Please practice patience over the first 7:32 of this Video – as we believe the intent of NOVA was to provide “entertainment value.”

 

We live in an age when technological indocumentarytion seems to be limitlessly soaring. But for all the satisfying speed with which our gadgets have improved, many of them share a frustrating weakness: the batteries. Even though there have been some improvements in last century, batteries remain finicky, bulky, expensive, toxic and maddeningly short-lived.

 

The quest is on for a “super battery,” and the stakes in this hunt are much higher than the phone in your pocket. With climate change looming, electric cars and renewable energy sources like wind and solar power could hold keys to a greener future… if we can engineer the perfect battery.

 

In Search for the Super Battery, renowned gadget geek and host David Pogue explores the hidden world of energy storage, from the power–and danger–of the lithium-ion batteries we use today, to the bold indocumentarytions that could one day charge our world. He wants to uncover what the future of batteries has in store for our gadgets, our lives – and even our planet. Might the lowly battery be the breakthrough technology that changes everything?

3-D printing and nanotechnology, a mighty alliance to detect toxic liquids

As soon as it comes out of the printing nozzle, the solvent evaporates and the ink solidifies. It takes the form of filaments slightly bigger than a hair. The manufacturing work can then begin. Credit: Polytechnique Montréal

Carbon nanotubes have made headlines in scientific journals for a long time, as has 3D printing. But when both combine with the right polymer, in this case a thermoplastic, something special occurs: electrical conductivity increases and makes it possible to monitor liquids in real time. This is a huge success for Polytechnique Montréal.

The article “3D Printing of Highly Conductive Nanocomposites for the Functional Optimization of Liquid Sensors” was published in the journal Small. Renowned in the field of micro- and nanotechnology, Small placed this article on its back cover, a sure sign of the relevance of the research conducted by mechanical engineer Professor Daniel Therriault and his team. In practical terms, the result of this research looks like a cloth; but as soon as a liquid comes into contact with it, said cloth is able to identify its nature. In this case, it is ethanol, but it might have been another liquid. Such a process would be a terrific advantage to heavy industry, which uses countless toxic liquids.

A simple yet efficient recipe

While deceptively simple, the recipe is so efficient that Professor Therriault protected it with a patent. In fact, a U.S. company is already looking at commercializing this material printable in 3D, which is highly conductive and has various potential applications.

The first step: take a thermoplastic and, with a solvent, transform it into a solution so that it becomes a liquid. Second step: as a result of the porousness of this thermoplastic solution, carbon nanotubes can be incorporated into it like never before, somewhat like adding sugar into a cake mix. The result: a kind of black ink that’s fairly viscous and whose very high conductivity approximates that of some metals. Third step: this black ink, which is in fact a nanocomposite, can now move on to 3D printing. As soon as it comes out of the printing nozzle, the solvent evaporates and the ink solidifies. It takes the form of filaments slightly bigger than a hair. The manufacturing work can then begin.

Credit: Polytechnique Montréal

The advantages of this technology

The research conducted at Polytechnique Montréal is at the vanguard in the field of uses for 3D printers. The era of amateurish prototyping, like printing little plastic objects, belongs to the past. These days, all manufacturing industries, whether aviation, aerospace, robotics or medicine, etc., have set their sights on this technology.

There are several reasons for this. Firstly, the lightness of parts because plastic is substituted for metal. Then there is the precision of the work done at the microscopic level, as is the case here. Lastly, with the nanocomposite filaments usable at room temperature, conductivities can be obtained that approximate those of some metals. Better still, since the geometry of filaments can be varied, measures can be calibrated that make it possible to read the various electric signatures of liquids that are to be monitored.

A topical example: pipelines

At the connection points of pipes that form pipelines, there are flanges. The idea would be to factory- manufacture the pipes with flanges coated by 3D printing. The coating would be a nanocomposite whose electric signature is calibrated according to the liquid being transported – oil, for instance. If there is a leak and the liquid touches the printed sensors based on the concept developed by Professor Therriault and his team, an alert would sound in record time, and in a very targeted way. That’s a tremendous advantage, both for the population and the environment; in case of a leak, the faster the reaction time, the lesser the damages.

Explore further: Chinese scientists unveil liquid phase 3-D printing method using low melting metal alloy ink

More information: Kambiz Chizari et al, Liquid Materials: 3D Printing of Highly Conductive Nanocomposites for the Functional Optimization of Liquid Sensors, Small (2016). DOI: 10.1002/smll.201670232

Journal reference: Small

Provided by: Polytechnique Montréal

 

Nanotechnology to “Super-Size” Green Energy

Nanotechnology is a field that’s receiving a lot of attention at the moment as scientists learn more every day about the benefits it can bring to both the environment and our health. There are various ways in which nanotechnology has proved itself useful including in developing enhanced solar cells and more efficient rechargeable batteries, and in saving raw materials and energy.

 

When it comes to nanotechnology, even the smallest achievements make huge differences, and on November 23, 2016, future technologies were presented to the international congress as part of the “Next Generation Solar Energy Meets Nanotechnology.” Out of the ten projects, three of them were located in Wurzburg and are explained in a little more detail below:

• Eco-friendly inks for organic solar cells: Over at the University of Erlangen-Nuremberg, Professors Vladimir Dyakonov and Christoph Brabec have created eco-friendly photovoltaic inks using nanomaterials and have developed a new simulation process at the same time. Dyakonov explains, “They allow us to predict which combinations of solvents and materials are suitable for the eco-friendly production of organic solar cells.”

• Nanodiamonds for ultra-fast electrical storage: If we want to have powerful, yet highly efficient electric vehicles then we need some way of storing the energy as a standard battery couldn’t handle it. Supercapacitors are great regarding acting as an efficient energy storage system. But, because their energy density is so low they need to be quite large in order to deliver any reasonable amount of energy. However, further work is being done in this area currently, and progress is promising.  Professor Anke Kruger, head of the project, says “Based on these findings, it is now possible to build application-oriented energy stores and test their applicability.”

 

• Increased storage capacity of hybrid capacitors: Better energy storage systems were also the focus of Professor Gerhard Sextl and his team’s project. Their hybrid capacitors can store more energy due to the embedded lithium ions and can do it quickly through the use of a supercapacitor. Sextl says, “We have managed to develop a material that combines the advantages of both systems. This has brought us one step closer to implementing a new, fast and reliable storage concept.”

Read More:

Read the rest of the story (click here) NEW SUPER-BATTERIES ARE FINALLY HERE

Company HE3DA President Jan Prochazka shows qualities of a new battery during the official start of a battery production line in Prague, on Monday, Dec. 19, 2016. The new battery is based on nanotechnology and is supposed to be be more efficient, long-lasting, cheaper, lighter and above all safer. The battery is designed to store energy from renewable electric sources and cooperate with smart grids. Next planned type will be suitable for electric cars. (Michal Kamaryt /CTK via AP)

It’s been a long time coming, but the wait is now over for a battery that lasts longer than your milk. Having to replace batteries in games, remotes, and other electrical devices are annoying, especially when you seem to be doing it every month. But, that may all be a thing of the past thanks to the Prague-based company, HE3DA. New superbatteries have finally been created that are capable of charging faster and lasting longer than any other technology out there and are being mass produced as you read this.

 

Oak Ridge National Laboratory: A NANOTECH WAFER TURNS CARBON DIOXIDE INTO ETHANOL ~ Potential for Future Renewable Energy Storage

TECHNIQUE TO CREATE ALCOHOL FROM THIN AIR HAS APPLICATIONS IN RENEWABLE ENERGY

Now before you conjure up images of “Animal House and John Belushi” … this is NOT the latest Frat House entry into “home brews!” The Researchers at ORNL have found a way to produce a potential fuel and energy storage for renewable energy sources using Nanotechnology – converting carbon dioxide – Alex Rondinone, the lead researcher says, “it’s like pushing combustion backwards– ….”

Ethanol

 

Ethanol’s popularity stems from the fact that it’s a major component of booze, but it has also seen use in recent years as a bio-fuel. Scientists have found a way to take everyone’s least favorite greenhouse gas, carbon dioxide, and mix it with water to create alcohol.

 

A research team at Oak Ridge National Laboratory in Tennessee developed a way to convert carbon dioxide into ethanol--and they did it by accident. Originally, they were hoping to convert carbon dioxide that had been dissolved in water to methanol, a chemical released naturally by volcanic gases and microbes, which can cause blindness in humans if ingested.

But instead of methanol, they discovered they had ethanol, a primary component of gin and also a potential fuel source. Surprised, the team realized that not only was their new material converting the carbon dioxide to ethanol, it needed very little outside support.

The material is a small chip–about a square centimeter in size–covered in spikes, each just a few atoms across. Each spike is constructed out of nitrogen with a carbon sheath and a small sphere of copper embedded in each tip. The chip is dipped into water and carbon dioxide is bubbled in. The copper acts as a small lightning rod, attracting electricity and driving the first steps of the conversion of the carbon dioxide and water into ethanol, before the molecules move to the carbon sheath to finish the process.

Alex Rondinone, the lead researcher, says it’s like pushing combustion backwards–normally ethanol can burn with oxygen to produce carbon dioxide and water, as well as energy. But they’ve managed to reverse the process, supplying carbon dioxide and water, supplying it with electricity, and ending up with ethanol.

 

Oak Ridge National Laboratory Nanospikes used to produce ethanol

 

The new material relies on many, many small sphere of copper only a few atoms wide, held up by carbon sheaths surrounding a core of nitrogen. These immeasurably tiny structures handle the entire business of turning carbon dioxide and water into ethanol.

The new nano-structured material allowed the researchers to use widely available materials like copper instead of more expensive options like platinum. In the past, this has hampered the ability to manufacture a material like this at larger scales.

The team hopes that their material, because it’s made from more easily available components, will be able to scale up successfully.

Even though the process probably won’t help much with carbon dioxide in the atmosphere–Rondinone says it would be too energetically costly–he believes there is another way for this process to help meet energy demands.

Rondinone sees an opportunity to help with intermittent power sources like wind and solar. By capturing excess electricity generated by the process and storing it in the form of ethanol, it could be burned later when the wind turbines aren’t spinning or the sun isn’t shining.

Don’t plan on seeing a new Oak Ridge National Laboratory luxury brand of 130 proof liquor on the shelves anytime soon though. Although Rondinone says the ethanol is just like the ethanol you drink, it also contains trace quantities of formate, which is toxic to humans. He cautions, “I would not advise people to drink it without further purification.”

The “Nano-Tooth Fairy” – Nanoparticles Release Drugs to Reduce Tooth Decay

Therapeutic agents intended to reduce dental plaque and prevent tooth decay are often removed by saliva and the act of swallowing before they can take effect. But a team of researchers has developed a way to keep the drugs from being washed away.

Dental plaque is made up of bacteria enmeshed in a sticky matrix of polymers—a polymeric matrix—that is firmly attached to teeth. The researchers, led by Danielle Benoit at the University of Rochester and Hyun Koo at the University of Pennsylvania’s School of Dental Medicine, found a new way to deliver an antibacterial agent within the plaque, despite the presence of saliva.

Their findings have been published in the journal ACS Nano.

“We had two specific challenges,” said Benoit, an assistant professor of biomedical engineering. “We had to figure out how to deliver the anti-bacterial agent to the teeth and keep it there, and also how to release the agent into the targeted sites.”

To deliver the agent—known as farnesol—to the targeted sites, the researchers created a spherical mass of particles, referred to as a nanoparticle carrier. They constructed the outer layer out of cationic—or positively charged—segments of the polymers. For inside the carrier, they secured the drug with hydrophobic and pH-responsive polymers.

The positively-charged outer layer of the carrier is able to stay in place at the surface of the teeth because the enamel is made up, in part, of HA (hydroxyapatite), which is negatively charged. Just as oppositely charged magnets are attracted to each other, the same is true of the nanoparticles and HA. Because teeth are coated with saliva, the researchers weren’t certain the nanoparticles would adhere. But not only did the particles stay in place, they were also able to bind with the polymeric matrix and stick to dental plaque.

Since the nanoparticles could bind both to saliva-coated teeth and within plaque, Benoit and colleagues used them to carry an anti-bacterial agent to the targeted sites. The researchers then needed to figure out how to effectively release the agent into the plaque.

Farnesol is released from the nanoparticle carriers into the cavity-causing dental plaque. Credit: Michael Osadciw/University of Rochester 

A key trait of the inner carrier material is that it destabilizes at acidic—or low pH—levels, such as 4.5, allowing the drug to escape more rapidly. And that’s exactly what happens to the pH level in plaque when it’s exposed to glucose, sucrose, starch, and other food products that cause tooth decay. In other words, the nanoparticles release the drug when exposed to cavity-causing eating habits—precisely when it is most needed to quickly stop acid-producing bacteria.

The researchers tested the product in rats that were infected with Streptococcus mutans—a microbe that causes tooth decay. “We applied the test solutions to rats’ mouths twice daily for 30 seconds, simulating what a person might do using a mouth rinse morning and night,” said Hyun Koo, a professor in the Department of Orthodontics and co-senior author of the work. “When the drug was administered without the nanoparticle carriers, there was no effect on the number of cavities and only a very small reduction in their severity. But when it was delivered by the nanoparticle carriers, both the number and severity of the cavities were reduced.”

Plaque formation and tooth decay are chronic conditions that need to be monitored through regular visits to the dental office. The researchers hope their results will someday lead to better—and perhaps permanent—treatments for dental plaque and tooth decay, as well as other biofilm-related diseases.

Graphene displays clear prospects for flexible electronics: U of Manchester

Published in the scientific journal Nature Materials, University of Manchester and University of Sheffield researchers show that new 2D ‘designer materials’ can be produced to create flexible, see-through and more efficient electronic devices.

The team, led by Nobel Laureate Sir Kostya Novoselov, made the breakthrough by creating LEDs which were engineered on an atomic level.

The new research shows that graphene and related 2D materials could be utilised to create light emitting devices for the next-generation of mobile phones, tablets and televisions to make them incredibly thin, flexible, durable and even semi-transparent.

The LED device was constructed by combining different 2D crystals and emits light from across its whole surface. Being so thin, at only 10-40 atoms thick, these new components can form the basis for the first generation of semi-transparent smart devices.

One-atom thick graphene was first isolated and explored in 2004 at The University of Manchester. Its potential uses are vast but one of the first areas in which products are likely to be seen is in electronics. Other 2D materials, such as boron nitiride and molybdenum disulphide, have since been discovered opening up vast new areas of research and applications possibilities.

By building heterostructures – stacked layers of various 2D materials – to create bespoke functionality and introducing quantum wells to control the movement of electrons, new possibilities for graphene based optoelectronics have now been realised.

Freddie Withers, Royal Academy of Engineering Research Fellow at The University of Manchester, who led the production of the devices, said: “As our new type of LED’s only consist of a few atomic layers of 2D materials they are flexible and transparent. We envisage a new generation of optoelectronic devices to stem from this work, from simple transparent lighting and lasers and to more complex applications.”

Explaining the creation of the LED device Sir Kostya Novoselov said: “By preparing the heterostructures on elastic and transparent substrates, we show that they can provide the basis for flexible and semi-transparent electronics.

“The range of functionalities for the demonstrated heterostructures is expected to grow further on increasing the number of available 2D crystals and improving their electronic quality.”

Prof Alexander Tartakovskii, from The University of Sheffield added: “The novel LED structures are robust and show no significant change in performance over many weeks of measurements.

“Despite the early days in the raw materials manufacture, the quantum efficiency (photons emitted per electron injected) is already comparable to organic LEDs.”

Explore further: Beyond graphene: Controlling properties of 2D materials

More information: Light-emitting diodes by band-structure engineering in van der Waals heterostructures, DOI: 10.1038/nmat4205