Integration Of Photonic And Electronic Components


QDOTS imagesCAKXSY1K 8Better integration of photonic and electronic components in nanoscale devices may now become possible, thanks to work by Khuong Phuong Ong and Hong-Son Chu from the A*A*STAR Institute of High Performance Computing and their co-workers in Singapore and the US. From computer simulations, they have identified that the compound BiFeO3 has the potential to be used to efficiently couple light to electrical charges through light-induced electron oscillations known as plasmons. The researchers propose that this coupling could be activated, controlled and switched off, on demand, by applying an electrical field to an active plasmonic device based on this material. If such a device were realized on a very small footprint it would give scientists a versatile tool for connecting components that manipulate light or electric currents.

poles

Thin poles standing in water barely affect waves rolling past them. Similarly, nanostructured devices typically do not interact with light waves

Many devices used in everyday life — whether they be televisions, mobile phones or barcode scanners — are based on the manipulation of electric currents and light. At the micro- and nano-scales, however, it is typically challenging to integrate electronic components with photonic components. At these small dimensions, the wavelengths of light become long relative to the size of the device. Consequently, the light waves are barely detectable by the device, just as passing waves simply roll past thin poles in a water body (see image).

“The fact that, in theory, the properties of BiFeO3 [could] be [so readily controlled] by applying an electric field makes it a promising material for high-performance plasmonic devices,” explains Ong. He says that they expected such favorable properties after they had calculated the behavior of the material. But when they studied the behavior of the proposed BiFeO3-based device, they found that it could outperform devices based on BaTiO3, which is one of the best materials currently used for such applications.

Like BaTiO3, BiFeO3 can be fabricated relatively easily and cheaply. The new material is therefore a particularly promising candidate for device applications. Ong, Chu and their collaborators will now explore that potential. “We will design BiFeO3 nanostructures optimized for applications such as optical devices for data communication, sensing and solar-energy conversion,” says Ong.

According to Ong and Chu, an important step on the path to producing practical devices will be assessing the compatibility of BiFeO3-based structures with standard technologies, which typically use materials known as metal-oxide semiconductors. This future work will involve collaborations with experimental groups at the A*STAR Institute of Materials Research and Engineering and at the National University of Singapore.

 

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance

 

Nanotechnology explained: Nanowires and nanotubes


nanomanufacturing-2Nanowerk News) Nanowires and nanotubes, slender structures that are  only a few billionths of a meter in diameter but many thousands or millions of  times longer, have become hot materials in recent years. They exist in many  forms — made of metals, semiconductors, insulators and organic compounds — and  are being studied for use in electronics, energy conversion, optics and chemical  sensing, among other fields.

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This Scanning Electron Microscope image shows an array of nanowires. (Photo:  Kristian Molhave/Opensource Handbook of Nanoscience and Nanotechnology)

The initial discovery of carbon nanotubes — tiny tubes of pure  carbon, essentially sheets of graphene rolled up unto a cylinder — is generally  credited to a paper published in 1991 by the Japanese physicist Sumio Ijima  (although some forms of carbon nanotubes had been observed earlier). Almost  immediately, there was an explosion of interest in this exotic form of a  commonplace material. Nanowires — solid crystalline fibers, rather than hollow  tubes — gained similar prominence a few years later.
Due to their extreme slenderness, both nanotubes and nanowires  are essentially one-dimensional. “They are quasi-one-dimensional materials,” says MIT associate professor of materials science and engineering Silvija  Gradecak: “Two of their dimensions are on the nanometer scale.” This  one-dimensionality confers distinctive electrical and optical properties.
For one thing, it means that the electrons and photons within  these nanowires experience “quantum confinement effects,” Gradecak says. And  yet, unlike other materials that produce such quantum effects, such as quantum  dots, nanowires’ length makes it possible for them to connect with other  macroscopic devices and the outside world.
The structure of a nanowire is so simple that there’s no room  for defects, and electrons pass through unimpeded, Gradecak explains. This  sidesteps a major problem with typical crystalline semiconductors, such as those  made from a wafer of silicon: There are always defects in those structures, and  those defects interfere with the passage of electrons.
Made of a variety of materials, nanowires can be “grown” on many  different substrates through a vapor deposition process. Tiny beads of molten  gold or other metals are deposited on a surface; the nanowire material, in  vapor, is then absorbed by the molten gold, ultimately growing from the bottom  of that bead as a skinny column of the material. By selecting the size of the  metal bead, it is possible to precisely control the size of the resulting  nanowire.
In addition, materials that don’t ordinarily mix easily can be  grown together in nanowire form. For example, layers of silicon and germanium,  two widely used semiconductors, “are very difficult to grow together in thin  films,” Gradecak says. “But in nanowires, they can be grown without any  problems.” Moreover, the equipment needed for this kind of vapor deposition is  widely used in the semiconductor industry, and can easily be adapted for the  production of nanowires.
While nanowires’ and nanotubes’ diameters are negligible, their  length can extend for hundreds of micrometers, even reaching lengths visible to  the unaided eye. No other known material can produce such extreme  length-to-diameter ratios: millions of times longer than they are wide.
Because of this, the wires have an extremely high ratio of  surface area to volume. That makes them very good as detectors, because all that  surface area can be treated to bind with specific chemical or biological  molecules. The electrical signal generated by that binding can then easily be  transmitted along the wire.
Similarly, nanowires’ shape can be used to produce narrow-beam  lasers or light-emitting diodes (LEDs), Gradecak says. These tiny light sources  might someday find applications within photonic chips, for example — chips in  which information is carried by light, instead of the electric charges that  relay information in today’s electronics.
Compared to solid nanowires, nanotubes have a more complex  structure: essentially one-atom-thick sheets of pure carbon, with the atoms  arranged in a pattern that resembles chicken wire. They behave in many ways as  one-dimensional materials, but are actually hollow tubes, like a long,  nanometer-scale drinking straw.
The properties of carbon nanotubes can vary greatly depending on  how they are rolled up, a property called chirality. (It’s similar to the  difference between forming a paper tube by rolling a sheet of paper lengthwise  versus on the diagonal: The different alignments of fibers in the paper produce  different strength in the resulting tubes.) In the case of carbon nanotubes,  chirality can determine whether the tubes behave as metals or as semiconductors.
But unlike the precise manufacturing control that is possible  with nanowires, so far methods for making nanotubes produce a random mix of  types, which must be sorted to make use of one particular kind. Besides  single-walled nanotubes, they also exist in double-walled and multi-walled  forms.
In addition to their useful electronic and optical properties,  carbon nanotubes are exceptionally strong, and are used as reinforcing fibers in  advanced composite materials. “In any application where one-dimensionality is  important, both carbon nanotubes and nanowires would provide benefits,” Gradecak  says.
  Source: By David L. Chandler,  MIT

Read more: http://www.nanowerk.com/news2/newsid=29945.php#ixzz2QGrCx84G

Read more: http://www.nanowerk.com/news2/newsid=29945.php#ixzz2QGr3jbwu

 

 

 

 

 

 

 

 

 

 

 

 

Read more: http://www.nanowerk.com/news2/newsid=29945.php#ixzz2QGqH8gFt

Flexible electronics could transform the way we make and use electronic devices


Flexible electronics open the door to foldaway smartphone displays, solar cells on a roll of plastic and advanced medical devices — if we can figure out how to make them.

QDOTS imagesCAKXSY1K 8Nearly everyone knows what the inside of a computer or a mobile phone looks like: A stiff circuit board, usually green, crammed with chips, resistors, capacitors and sockets, interconnected by a suburban sprawl of printed wiring.

But what if our printed circuit board was not stiff, but flexible enough to bend or even fold?

It may sound like an interesting laboratory curiosity, but not to Enrique Gomez, an assistant professor of chemical engineering at Penn State. “It could transform the way we make and use electronic devices,” he says.

Gomez is one of many scientists investigating flexible electronics at the University’s Materials Research Institute. Others are doing the same at universities and corporations around the world.

Flexible electronics are in vogue for two reasons.

First, they promise an entirely new design tool. Imagine, for example, tiny smartphones that wrap around our wrists, and flexible displays that fold out as large as a television. Or photovoltaic cells and reconfigurable antennas that conform to the roofs and trunks of our cars. Or flexible implants that can monitor and treat cancer or help paraplegics walk again.

Penn State’s interest in flexible and printed electronics is not just theoretical. In October 2011, the University began a multi-year research project with Dow Chemical Corporation. Learn more about the partnership.

Second, flexible electronics might cost less to make. Conventional semiconductors require complex processes and multi-billion dollar foundries. Researchers hope to print flexible electronics on plastic film the same way we print ink on newspapers.

“If we could make flexible electronics cheap enough, you could have throwaway electronics. You could wear your phone on your clothing, or run a bioassay to assess your health simply by wiping your nose with a tissue,” Gomez says.

Before any of this happens, though, researchers have to rethink what they know about electronics.

Victim of Success

That means understanding why conventional electronics are victims of their own success, says Tom Jackson, Kirby Chair Professor of Electrical Engineering. Jackson should know, because he helped make them successful. Before joining Penn State in 1992, he worked on IBM‘s industry-leading laptop displays. At Penn State, he pioneered the use of organic molecules to make transistors and electronic devices.

Modern silicon processors integrate billions of transistors, the semiconductor version of an electrical switch on tiny slivers of crystalline silicon.

Squeezing so many transistors in a common location enables them to handle complex problems. As they shrink in size, not only can we fit more transistors on a chip, but the chip gets less expensive to manufacture.

“It is hard to overstate how important this has been,” Jackson explains.

“Remember when we paid for long-distance phone calls by the minute? High-speed switching drove those costs way down. In some cases, we can think of computation as free. You can buy an inexpensive calculator at a store for $1, and the chip doesn’t even dominate the cost. The power you get is amazing.”

That, says Jackson, is the problem. Semiconductor processors are so good and so cheap, we fall into the trap of thinking they can solve every problem.

Sometimes, it takes more flexibility to succeed.

Electronics-research-001

Consider surgery to remove a tumor from a patient’s liver. Even after following up with radiation or chemotherapy, the surgeon is never sure if the treatment was successful.

“But suppose I could apply a flexible circuit to the liver and image the tissue. If we see a new malignancy, it could release a drug directly onto that spot, or heat up a section of the circuit to kill the malignant cells. And when we were done, the body would resorb the material,” Jackson says.

“What I want,” he says, “is something that matches the flexibility and thermal conductivity of the body.” Conventional silicon technology is too stiff and thermally conductive to work.

Similarly, large, flexible sensors could monitor vibrations on a bridge or windmill blade and warn when they needed maintenance.

“If you want to spread 100 or 1,000 sensors over a large area, you have to ask whether you want to place all the chips you need to do that, or use low-cost flexible electronics that I can apply as a single printed sheet,” Jackson says.

None of the flexible electronics now under development would match the billions of transistors that now fit on silicon chips, or their billions of on-off cycles per second. They would not have to. After all, even today’s fastest televisions refresh their displays only 240 times per second. That is more than fast enough to image cancer in the body, reconfigure an antenna, or assess the stability of a bridge.

So how, exactly, do we make flexible electronics, and what kind of materials do we make them from?

Printing

To explain what draws researchers to printing flexible electronics, Jackson walks through the production of flat panel displays in a $2-3 billion factory.

The process starts with a 100-square-foot plate of glass. To apply wires, the factory coats the entire plate with metal, then covers it with a photosensitive material called a resist. An extremely bright light flashes the pattern of the wires onto the coating, hardening the resist. In a series of steps, the factory removes the unhardened resist and metal under it. Then, in another series of steps, it removes the hardened resist, leaving behind the patterned metal wires.

Factories repeat some variant of this process four or five times as they add light-emitting diodes (LEDs), transistors and other components. With each step, they coat the entire plate and wash away unused materials. While the cost of a display is 70 percent that of a finished device, most of those materials get thrown away.

None of the flexible electronics now under development would match the billions of transistors that now fit on silicon chips, or their billions of on-off cycles per second. They would not have to.

“So it’s worth thinking about whether we can do this by putting materials where we need them, and reduce the cost of chemicals and disposal. It is a really simple idea and really hard to do,” Jackson says.

An ideal way to do that, most researchers agree, would be to print the electronics on long plastic sheets as they move through a factory. A printer would do this by applying different inks onto the film. As the inks dried, they would turn into wires, transistors, capacitors, LEDs and all the other things needed to make displays and circuits.

That, at least, is the theory. The problem, as anyone who ever looked at a blurry newspaper photograph knows, is that printing is not always precise. Poor alignment would scuttle any electronic device. Some workarounds include vaporizing or energetically blasting materials onto a flexible sheet, though this complicates processing.

And then, of course, there are the materials. Can we print them? How do we form the precise structures we need? And how do we do dry and process them at temperatures low enough to keep from melting the plastic film?

Material World

Fortunately, there are many possible materials from which to choose. These range from organic materials, like polymers and small carbon-based molecules, to metals and even ceramics.

At first glance, flexible ceramics seem like a stretch. Metals bend, and researchers can often apply them as zigzags so they deform more easily.

Try flexing a thick ceramic, though, and it cracks. Yet that has not deterred Susan Trolier-McKinstry, a professor of ceramic science and engineering and director of Penn State’s W.M. Keck Smart Materials Integration Laboratory.

Ceramics, she explains, are critical ingredients in capacitors, which can be used to regulate voltage in electronic circuits. In many applications, transistors use capacitors to provide instantaneous power rather than waiting for power from a distant source.

Industry makes capacitors from ultrafine powders. The tiniest layer thicknesses are 500 nanometers, 40 times smaller than a decade or two ago. Even so, there is scant room for them on today’s overcrowded circuit boards, especially in smartphones. Furthermore, there is a question about how long industry can continue to scale the thickness in multilayer ceramic capacitors.

Trolier-McKinstry thinks she can deposit smaller capacitors directly onto flexible sheets of plastic, and sandwich these in flexible circuit board. That way, the capacitors do not hog valuable surface area.

One approach is to deposit a precursor to the capacitor from a solution onto a plastic film and spot heat each capacitor with a laser to remove the organics and crystallize the ceramic into a capacitor. Another approach is to use a high-energy laser beam to sand blast molecules off a solid ceramic and onto a plastic substrate.

As long as she can keep capacitor thicknesses small, Trolier-McKinstry need not worry too much about capacitor flexibility. Previous researchers have demonstrated that it is possible to bend some electroceramic films around the radius of a Sharpie pen without damage.

Of course, not every element placed on a flexible substrate will be small. So what happens if your transistors need to bend?

One way to solve that problem is to make electronics from organic materials like plastics. These are the ultimate flexible materials. While most organics are insulators, a few are conductive.

“Organic molecules have tremendous chemical versatility,” Gomez explains. “My group’s goal is to turn these molecules into transistors and photovoltaic cells.” Easier said than done. The almost infinite number of possibilities available in organic chemistry, he says, make it challenging to find the right combination of structure, properties and function to create an effective device.

Molecules may not be picky about their neighbors, but they still need to form the right type of structures to act as switches or turn light into electricity. Gomez attacks the problem by using a technique called self-assembly. It starts with block copolymers, combinations of two molecules with different properties bound together in the middle.

Trolier-McKinstry thinks she can deposit smaller capacitors directly onto flexible sheets of plastic, and sandwich these in flexible circuit boards. That way, the capacitors do not hog valuable surface area.

“Think of them as a dog and a cat tied together by their tails,” Gomez explains. “Ordinarily, they want to run away from each other, but now they can’t. Then we throw them into a room with other tied dogs and cats. What happens is that all the cats wind up on one side of the room and the dogs on the other, so they don’t have to look at each other.”

Gomez believes this process could enable him to build molecules programmed to self-assemble into electronic structures at very low cost.

“The overarching problem,” Gomez continues, “is figuring out how to design the molecule and then tickle it with pressure, temperature and electrical fields to form useful structures. We don’t really understand enough to do that yet.”

Despite the challenge, flexible electronics promise changes that go beyond folding displays, inexpensive solar cells, antennas and sensors. They could veer off in some unexpected directions, such as helping paraplegics walk again.

Mimicking Jell-O

That is the goal of Bruce Gluckman, associate director of Penn State’s Center for Neural Engineering. To get there, he must learn how the brain’s neurons collaborate.

“Computations happen at the level of single neurons that connect to other neurons. Half the brain is made up of the wiring for these connections, and any cell can connect to a cell next to it or to a cell across the brain. It’s not local in any sense,” he explains.

Scientists measure the electrical activity of neurons by implanting silicon electrodes into the brain. Unfortunately, Gluckman says, the brain is as spongy as Jell-O and the electrode is as stiff as a knife.

Plunging the electrode into the brain causes damage immediately. Every time the subject moves its head, the brain pulls away from the electrode on one side and makes better contact on the other. It takes racks of electronics to separate the signal from the noise of such inconsistent output.

“This is why we need something other than silicon,” Gluckman says.

Despite the challenge, flexible electronics promise changes that go beyond folding displays, inexpensive solar cells, antennas and sensors. They could veer off in some unexpected directions, such as helping paraplegics walk again.

Flexible electronics would better match the brain’s springiness. While some researchers are looking at all-organic electrodes, Gluckman believes they are too large and too slow to achieve the resolution he needs. Instead, he has teamed with Jackson to develop a flexible electrode based on zinc oxide, a faster semiconductor that can be deposited on plastic at low temperatures.

The work is still in its early stages, but Gluckman believes they can develop a reliable electrode that lasts for years and produces stronger, clearer signals.

Researchers have already demonstrated that humans can control computer cursors, robotic arms and even artificial voice boxes with today’s problematic electrodes. Yet the results are often short-lived.

“No one is going to let you operate on their brain twice,” Gluckman says. “If you want to directly animate limbs with an implant, the implant has to last the life of the patient. If we can do that, we can enable paraplegics to get around on their own.”

As Jackson notes, computers and smartphones may have powered silicon’s development, but the results are visible in everything from cars and digital thermometers to toys and even greeting cards.

Displays and solar cells are likely to power the new generation of flexible electronics, but brain implants are just one of the many unexpected directions they may take.

Enrique Gomez is assistant professor of chemical engineering, edg12@psu.edu. Thomas N. Jackson is Kirby Chair Professor of Electrical Engineering, tnj1@psu.edu. Susan Trolier-McKinstry is professor of ceramic science and engineering and director of the W.M. Keck Smart Materials Integration Laboratory, STMcKinstry@psu.edu. Bruce Gluckman is associate director of Penn State’s Center for Neural Engineering, bjg18@psu.edu.

Nanotech commercialization conference to showcase NC’s advances


By JIM ROBERTS, special to WRALTechWire

QDOTS imagesCAKXSY1K 8Winston-Salem, N.C. — Just like Easter, visible groundhogs and the Opening Day of baseball season are symbolic rites of Spring, so is the annual Nanotechnology Commercialization Conference.

 

 

This year’s North Carolina-hosted event, which opens Tuesday, will be held at the new $100 million investment and renovated Biotech Place in downtown Winston-Salem. The conference will showcase Wake Forest University technologies with people such as Dr. Tony Atala, Dr. David Carroll and NanoMedica CEO Roger Cubicciotti among others in the Triad, across North Carolina and beyond.

Nano particles at Liquidia.

This fifth annual conference is a partnership among the NC Department of Commerce, the North Carolina Office of Science & Technology, the Center of Innovation for NanoBiotechnology (COIN) and the Nanotech Commercialization Association.

While many will argue that nanotechnology is not a truly independent industry, it can still have a large impact on the state’s economy, and North Carolina is ahead of the curve among the southeastern neighbors. North Carolina is competitive with California and Massachusetts in nanobiotechnology, the intersection of advanced materials and life sciences as defined by COIN.

Products incorporating nanotech are most likely going to be an input to another industry’s products such as coatings, carriers, composites, communications or catalysis. Drug delivery (carrier) also uses coatings. Aerospace uses coatings and composites. IT and Communications devices use nanotech and microelectronics. The next generation of batteries and the energy industries are using nano for catalysis.

Nanotech conference

Even when North Carolina-based Liquidia Technologies was featured in the NY Times, the company was mentioned as a biotech company, not a nanotech company.

Resources for Nano Companies in North Carolina

North Carolina nanotech companies have made some progress in finding funding over the last five years. Liquidia is the obvious example as they have raised over $50 million dollars including from the Bill and Melinda Gates Foundation making an equity investment, GSK, Pappas Ventures, PPD, Wakefield Group and others. Xanofi announced an angel round and has found some international investors. Duke spinout Nanoly won the 2012 Duke Startup Challenge Business Plan competition. Blue Nano was featured as a presenting company at the 2013 SEVC conference in Charlotte last month. North Carolina resident Rob Burns has recently joined the nano related VC firm Harris and Harris. NanoMedica in Winston Salem has recently received a large Phase II SBIR grant from NIH.

North Carolina has been promoting the nanotech sector through a series of conferences and bringing in international conferences such as the MANCEF COMS Conference that brought industry professionals from 17 different countries to the Greensboro area in 2010. North Carolina has also created the Joint School of NanoScience and NanoEngineering and the NC Biotech Center created the Center of Innovation for NanoBiotechnology.

While North Carolina as a state has invested in the infrastructure for nanotechnology, the private sector results are harder to showcase as again they are often included in other industries. The first graduate of the Joint School of Nano got her first internship and first job at Kymanox, a small industry products and services firm based in RTP. The FDA has been slow to give more regulatory guidance on nanotechnology and as a result the investors have been on the sidelines for the most part. And until there is more private sector investment and regulatory guidance, the nanotech sector will struggle to show job creation as a result of this infrastructure investment.

There were some whispers of interest in funding of nano research at the Southeast Venture Philanthropy Summit last week.

North Carolina makes a real effort to move this nanotech conference around the areas of the state that have a cluster of nanotechnology with the events held in Greensboro, Winston Salem, Raleigh-Durham and Charlotte with UNC Charlotte.

Who in North Carolina Is Making an Impact?

North Carolina is once again set to showcase some of the stars of the industry. Most industry followers are familiar with the Joe DeSimone and Neal Fowler, leaders of Liquidia and with Dr. Tony Atala of the Wake Forest Institute for Regenerative Medicine. The conference will also showcase other emerging leaders and their companies. Xanofi will have a different executive on a panel but the other leaders listed below will play a major role in the conference. (The biographies below are a combination of conference listings, company web site content and personal knowledge.)

  • Ginger Rothrock – Research Triangle Institute International

While Dr. Rothrock was a co-founder in the nanotechnology company Liquidia Technologies, she is now working in the nano space in the energy industries for research powerhouse Research Triangle Institute International (RTI). Dr. Rothrock is the Program Manager for Emerging Technologies at RTI, where she is responsible for business and technical development for new strategic areas in RTI’s nanotechnology portfolio. Dr. Rothrock acts as principal investigator and program manager for a number of R&D programs for nano-enabled products in building materials, composites and controlled release systems. Dr. Rothrock gained valuable experience working at Novartis, Los Alamos National Laboratory, and the EPA prior to her founding work at Liquidia

  • Miles Wright – Xanofi

Miles Wright is a well-known business leader and serial entrepreneur in the Raleigh area. His new company Xanofi has taken NC State technology to create a new way to develop nanofibers for the air filtration industry and other industries such as acoustics. Xanofi has successfully raised early stage funds and hired a small staff in the last two years with the help of new international partnerships.

  • David N. Himebaugh – Blue Nano

David N. Himebaugh, COO & President, North America.  Mr. Himebaugh has 25 years of experience running his own businesses. Mr. Himebaugh brings an acute ability to define the correct strategic direction for new businesses, experience in capturing high growth opportunities while managing costs, and ethical leadership.  Blue Nano is aiming to become the leader as the premier provider for silver nanowires and catalysts. Blue Nano is a nanomaterials manufacturer that develops high quality, cost effective and reliable nano-focused industrial solutions in the highest volumes available anywhere. Blue Nano serves universities, independent research labs and OEM manufacturers in a wide variety of sectors ranging from automotive to energy to healthcare.

  • Professor David L. Carroll, Ph.D. – Wake Forest University

David Carroll is a physicist and nanotechnologist, Fellow of the Society of Nanoscience and Nanotechnology, and director of the Center for Nanotechnology and Molecular Materials at Wake Forest University. He has contributed to the field of nanoscience and nanotechnology through his work in nanoengineered cancer therapeutics, nanocomposite-based display and lighting technologies, and high efficiency nanocomposite photovoltaics.

Professor Carroll’s academic research is focused on the synthesis, assembly, characterization, and applications of nanostructures. He holds 12 patents. Prof. Carroll has been actively involved in four spin-off companies utilizing technologies from his labs. Prof. Carroll earned his BS in physics from NC State University and his PhD in physics from Wesleyan University.

Why quantum dots can join every aspect of everyday life


nanomanufacturing-2Nanotechnology is often confined to niche products, but quantum dots are so versatile they could be used in everything from light bulbs to laptops.

 

The properties of a material were once thought to be defined only by its chemical composition. But size matters too, especially for semiconductors. Make crystals of silicon small enough – less than 10 nanometres – and their tiny dimensions can start to dictate how the atoms behave and react in the presence of other things.

These tiny bits of semiconductor crystals – so-called quantum dots – have such remarkable, novel properties that scientists think they will soon be used in everything from light bulbs to imaging of cancer cells or in the design of ultra-efficient solar cells.

Semiconductors such as silicon or indium arsenide are chosen to build electronic circuits because of the discrete energy levels at which they can give off electrons or photons. This makes them useful in building switches, transistors and other devices. It was once thought these energy levels – known as band gaps – were fixed. But shrinking the physical size of the semiconductor material to quantum-dot level seems able to change the band gaps, altering the wavelengths of light the material can emit or changing the energy it takes to change a material from an insulator to a conductor.

Instead of looking for brand new materials to build different devices, then, quantum dots make it possible to use a single type of semiconductor to produce a range of different characteristics. Researchers could tune dots made from silicon to emit a range of different colours in different situations, for example, instead of having to use a range of materials with different chemical compositions.

Sheet of semiconductor crystals

Tiny bits of semiconductor crystals – so-called quantum dots – have such remarkable properties that scientists think they will soon be used in everything from light bulbs to the design of ultra-efficient solar cells. Photograph: Science Photo Library

“The main application for quantum dots at the moment is biological tagging of cells,” says Paul O’Brien, a professor of inorganic materials at the University of Manchester and co-founder of Nanoco Technologies a quantum dot manufacturer also based in Manchester. They are used in the same way as fluorescent dyes, to label agents, he says, but with the advantage that a single laser source can be used to illuminate many different tags each with a specific wavelength.

By attaching different types of quantum dots to proteins that target and attach to specific cell types in the body, these bits of semiconductor can be used by doctors to monitor different kinds of cells. When a laser is then directed on to tagged cells, doctors can see what colour they glow.

The ability to shine also makes quantum dots well suited to produce white light. Existing white bulbs based on low energy light emitting diode (LED) technology tend to produce a garish and bluish form of light that notoriously feels cold, says O’Brien. This is because these LEDs use a phosphor that produces an artificial white light that contains less red wavelengths than natural white light. By embedding quantum dots into a film that is placed over a bulb containing blue LEDs, it is possible to get a much warmer colour of white light. The blue light  from the LED stimulates the quantum dots which, in turn, emit light in a range of colours. Provided you have chosen your dots carefully, these will combine to form white light.

The first of these quantum dot lights hit the market in 2010, a partnership between QD Vision, an MIT spinout in Lexington, Massachusetts, and Nexxus Lighting of Charlotte, North Carolina.

Backlights for laptops, tablets and mobile devices are next in line, and they should appear in products before the end of 2012 says VJ Sahi, head of corporate development at materials design company Nanosys of Palo Alto, California. Besides the colour advantages, quantum-dot-based backlights can be three times more efficient than traditional backlights.

Eventually, says Sahi, quantum dots will do more than just light up displays. The long-term aim is use them to create each red, green and blue sub-pixel that makes up a coloured display. This should produce much brighter colours and consume less power than LCD or even the latest state-of-the-art organic LED (OLED) displays. They should also have no problems with viewing angles, he adds.

The interesting properties of quantum dots come from the fact that they behave like tuning forks for photons, a result of a phenomenon called confinement. At less than 10 nanometres in size – about 50 atoms – they fall within the dimensions of a critical quantum characteristic of the material known as the exciton Bohr radius. The energy levels of electrons within the material’s atoms are constrained and, when a photon or electron hits an atom and excites it, the atom re-emits the energy as a photon of a very specific energy level.

Quantum dots also have another trick up their sleeve. Besides converting photons of one energy into photons of another, they can also be used to release electrons and create electrical currents: in other words they can be used to make solar cells. Arthur Nozik at the National Renewable Energy Laboratory in Boulder, Colorado, says that quantum-dot solar cells would be much more efficient at converting the energy from photons and therefore boost the amount of power they can produce.

Such applications are many years from becoming commercial reality. But they serve to demonstrate that no material technology stands still; sometimes all you have to do is cut it down to size.

 For More on How “Nanotechnology” and “Quantum Dots” Will Impact the Future, Go To:

10 Ways Nano-Manufacturing Will Alter Industry

https://genesisnanotech.wordpress.com/2013/03/30/10-ways-nanomanufacturing-will-alter-industry/

The dos and don’ts of pitching to the media: MaRS Media Mashup


By Jennifer Marron @ MaRS

April 4, 2013

QDOTS imagesCAKXSY1K 8“Put it before them briefly so they will read it, clearly so they will appreciate it, picturesquely so they will remember it and, above all, accurately so they will be guided by its light.” — Joseph Pulitzer

 

 

*** Note to Readers: In a slightly off subject piece … as many of our readers are, or have been “entreprenuers” at one time or another (once a ‘e’, always and ‘e’!)  … and as we all have dealt with “Press Releases” and have either responded to a request or been the “request-ee” … we thought you would enjoy the ‘Media’s Perspective’ on all of us who “bring the pitch!”

Last week, five of Canada’s top journalists came to MaRS for our first-ever MaRS Media Mashup: Pitching the Press event in the MaRS Studio.

 

 

 

Eleven MaRS clients across all practices presented their two-minute verbal pitches to the distinguished panel of journalists, moderated by Wendy Bryan, former CTV producer and current senior advisor, new media and communications for the Ontario Ministry of Economic Development, Trade and Employment.

The session panellists included:

The interactive session included a panel discussion and interactive Q-and-A session with each startup after their pitch. The startups gained a better sense of which angles work best for some of Canada’s leading media outlets, as well as story ideas.

The five panellists also offered some dos and don’ts for startups interested in obtaining media coverage.

The dos

  • Be succinct and get to the point immediately. “People tend to bury the important information in the fourth paragraph. Bring this up to the top and explain what the story is about right off the bat. Get me excited.” — Sean Stanleigh
  • Do your homework. “Know who you’re pitching to and get to know the personality of the show/publication beforehand.” — Zena Olijnyk
  • Focus on the local news angle. “Ask, what’s your connection to the city/town you live in? Find real people in your story and don’t forget compelling visuals.” — Helen Bagshaw
  • Be clear and concise. “Be careful not to get spun in the wrong way. Be clear, concise and say your message three times.” — Dan Verhaeghe
  • If you can, use the venture capital angle. “If you’re working a prominent name, use this as a segue to gain journalist interest. Even if you’re just in talks with them, let the journalist know that there could be a story down the road.” — Jon Cook

The dont’s

  • “Don’t pitch a story without actually being ready for media coverage.” — Sean Stanleigh
  • “Don’t bombard a journalist with emails or pitch every single department within an organization, as we have no visibility into these.” — Zena Olijnyk
  • “Don’t pitch me a story just about ‘the really cool entrepreneur.’” — Helen Bagshaw
  • “Don’t give the same story idea to every journalist out there. Be sure to adjust to the changing realities of the media landscape.” — Dan Verhaeghe
  • “Don’t request to see articles before they are published. It’s not a press release.” — Jon Cook

The 11 MaRS startups that pitched at the event were:

Information technology, communications and entertainment (ICE) practice + JOLT Accelerator

Social innovation practice

Cleantech practice

Life sciences and healthcare practice

Vaporware: Scientists Use Cloud of Atoms as Optical Memory Device


QDOTS imagesCAKXSY1K 8Talk about storing data in the cloud. Scientists at the Joint Quantum Institute (JQI) of the National Institute of Standards and Technology (NIST) and the University of Maryland have taken this to a whole new level by demonstrating* that they can store visual images within quite an ethereal memory device—a thin vapor of rubidium atoms. The effort may prove helpful in creating memory for quantum computers.

This brief animation (click link to launch mp4) by the NIST/JQI team shows the NIST logo they stored within a vapor of rubidium atoms and three different portions of it that they were able to extract at will. Animation combines three actual images from the vapor extracted at different times.

Their work builds on an approach developed at the Australian National University, where scientists showed that a rubidium vapor could be manipulated in interesting ways using magnetic fields and lasers. The vapor is contained in a small tube and magnetized, and a laser pulse made up of multiple light frequencies is fired through the tube. The energy level of each rubidium atom changes depending on which frequency strikes it, and these changes within the vapor become a sort of fingerprint of the pulse’s characteristics. If the field’s orientation is flipped, a second pulse fired through the vapor takes on the exact characteristics of the first pulse—in essence, a readout of the fingerprint.

“With our paper, we’ve taken this same idea and applied it to storing an image—basically moving up from storing a single ‘pixel’ of light information to about a hundred,” says Paul Lett, a physicist with JQI and NIST’s Quantum Measurement Division. “By modifying their technique, we have been able to store a simple image in the vapor and extract pieces of it at different times.”

It’s a dramatic increase in the amount of information that can be stored and manipulated with this approach. But because atoms in a vapor are always in motion, the image can only be stored for about 10 milliseconds, and in any case the modifications the team made to the original technique introduce too much noise into the laser signal to make the improvements practically useful. So, should the term vaporware be applied here after all? Not quite, says Lett—because the whole point of the effort was not to build a device for market, but to learn more about how to create memory for next-generation quantum computers.

“What we’ve done here is store an image using classical physics. However, the ultimate goal is to store quantum information, which a quantum computer will need,” he says. “Measuring what the rubidium atoms do as we manipulate them is teaching us how we might use them as quantum bits and what problems those bits might present. This way, when someone builds a solid-state system for a finished computer, we’ll know how to handle them more effectively.”

*J.B. Clark, Q. Glorieux and P.D. Lett. Spatially addressable readout and erasure of an image in a gradient echo memory. New Journal of Physics, doi: 10.1088/1367-2630/15/3/035005, 06 March 2013.

Nanotechnology policy making – mandatory tools


Posted: Apr 3rd, 2013  By Michael Berger. Copyright © Nanowerk

Nanotechnology policy making – mandatory tools

QDOTS imagesCAKXSY1K 8(Nanowerk Spotlight) Governments are charged with  determining whether chemical substances, and products that include those  substances, can be used without adversely affecting humans and other living  beings. Science helps inform policy decisions by providing information on the  benefits and drawbacks of a technology or a product of that technology. So much  for the theory.

Currently, there are significant limitations in the  environmental, health and safety (EHS) data available for nanomaterials.  Furthermore, although a wide variety of test methods and guidance for regulatory  testing of bulk chemicals is available, a number of them will need significant  modification before being applicable to nanomaterials. Complicating things, science is quite divided on how to assess  nanotechnology materials and applications.

Consequently, as the public  discussion about the regulation of nanotechnology in general, and nanomaterials  in particular, heats up, emerging opinions on the applicability of existing  regulation differ substantially (read more: “Regulating  nanotechnology – how adequate is current regulation?”) and so do views on  which regulatory options best address the current lack of information about  environment, health and safety risks of nanomaterials, as well as the regulatory  uncertainty and concerns expressed by the politicians, members of the public and  industry, and investors (read more in our previous Nanowerk Spotlight: “Science  policy considerations for responsible nanotechnology decisions”).

A new, two-part survey in Global Policy (“The Challenges of Nanotechnology Policy Making PART 1. Discussing  Mandatory Frameworks” and “The Challenges of Nanotechnology Policy Making PART  2. Discussing Voluntary Frameworks and Options”), compiled by Claire  Auplat, a professor at the Novancia Business School, Paris, France, outlines  the different frameworks policy makers have developed. The first part of the  survey, which we are covering today in this Nanowerk Spotlight,  introduces nanotechnology policy making and the reasons for its complexity, and  offers a panorama of the set of mandatory tools that are currently  available to regulate nanotechnologies.

The second part, which will appear in  our Spotlight tomorrow, provides an outlook of the set of voluntary tools  that coexist with the mandatory ones. First, let’s look at the typology involved: Mandatory or voluntary regulationAs we will see, In nanotechnology, there are many initiatives of  voluntary regulation. These constitute new layers of regulation that  stakeholders decide to add to the mandatory ones which they must comply with. Geographic level of regulationRegulation happens at different levels, from the local one to  the international one.

The terms ‘international’, ‘regional’, ‘national’ and ‘local’ usually refer to the bodies which pass the said regulations, not to the  areas covered by them. The geographic scope of some regulations goes beyond that  of the body that passed them. To continue with the example of the EU regulation,  when a specific law targets the products or substances manufactured or imported  in the EU, its scope may in effect be much larger since it may impact producers  globally. The targets of regulationRegulation has two broad targets, either the products or  substances themselves, or those exposed to them, like people or the environment.  The distinction is not always clear-cut, but in the case of nanotechnology  regulation there is a trend to move from the former to the latter.

The following is a list of existing tools of mandatory  nanotechnology governance:

REACH, the Registration, Evaluation, Authorization and  Restriction of Chemical Substances – EC 1907/2006REACH is the European Community Regulation on  chemicals and their safe use (EC 1907/2006). It deals with the Registration,  Evaluation, Authorisation and Restriction of Chemical substances. The law  entered into force on 1 June 2007.

REACH is a general framework and it does not apply specifically  to nano substances. Critics of the law say that because most nano substances are  so small, they are produced in quantities that are below one tonne per year,  which means that they go unregulated. REACH can in fact apply to substances produced or imported in  volumes below 1 tonne per year if they are considered to be of very high  concern. This means in effect that risks from certain nano scale substances  could be addressed through REACH if they were identified as being ‘substances of  very high concern’ as defined in Article 57, for example as being persistent,  bio accumulative and toxic (PBT) substances. Novel food regulation, regulation EC 258 /  97-1997This European regulation laid out rules for the  authorisation of ‘novel’ foods.

According to a European Parliament press release of March 2011 the use of  nanotechnology in food production, for example as an antibacterial agent, or to  alter flavour or color is growing and the European Parliament called for further  checks to be developed to adequately assess the safety of such foods. They also  wanted food containing nano ingredients to be labelled. However, due to a  failure to reach agreement on the new rules ‘there will continue to be no  special measures regarding nanomaterials in food’ the EP statement said.

Regulation (EC) no 1223 / 2009 of the European  Parliament and of the council of 30 November 2009 on cosmetic  products.  This law – the first international law  specifically designed for nanotechnologies – includes a review of the safety of  nanomaterials and will take effect in July 2013, with gradual implementation  started in December 2010. All cosmetic products will be subject to a safety  assessment and to a premarket notification and approval procedure.

This law specifically sayes: “The Regulation prohibits the use  of substances recognised as carcinogenic, mutagenic or toxic for reproduction  (classified as CMR), apart from in exceptional cases. It provides for a high  level of protection of human health where nanomaterials are used in cosmetic  products.” The regulation also requires traceability of a cosmetic product  throughout the whole supply chain, as well as clear labelling including the name  and address of the responsible person, and the presence of all ingredients  containing nanomaterials, with their names followed by (nano).

Toxic substances control act inventory status of carbon  nanotubes. Generally speaking, the US Toxic Substances Control Act (TSCA)  regulates all chemical substances. However, since the passing of the TSCA Inventory Status of Carbon Nanotubes in 2008, some  nanomaterials have been considered as specific chemical substances and are  therefore subject to special regulation.

Federal insecticide, fungicide, and rodenticide  act. Under this U.S. federal regulation, all pesticides  distributed or sold in the U.S. must be registered by the Environmental  Protection Agency (EPA). The EPA ruled in 2006 that the Samsung silver  ion generating washing machine, which released nano silver ions into wash  water, was subject to registration requirements under FIFRA because it  incorporated a substance intended to prevent, destroy or mitigate pests, and was  therefore considered a pesticide.

DTSC chemical call in: carbon nanotubes, quantum dots,  nanosilver,  nano cerium oxide, nano titanium dioxide, and nano zinc  oxide. California law authorizes the Department of Toxic Substances  Control to request information regarding analytical test methods, fate and  transport in the environment, and other relevant information about specified  chemicals. The Department has conducted two chemical information call-ins. In 2010,  Round One sought information on carbon nanotubes.  In 2011, Round Two sought  information on quantum dots, nanosilver, nano zero valent iron, nanocerium  oxide, nanotitanium dioxide, and nanozinc oxide.  Visit Round One and Round Two for the responses from manufacturers  and importers of these chemical substances.

The manufactured nano scale health and safety ordinance.  Section 15.12.040 Berkeley city council ordinance.  This municipal ordinance was passed in December  2006 by the city council of Berkeley, CA, and was the first case in the world of  mandatory regulation specifically targeted at nanotechnologies. It amended  existing health and safety rules to demand a full toxicological report from all  facilities manufacturing nanoparticles.

NIOSH Current Intelligence Bulletin (CIB) 63 on  occupational exposure to titanium dioxide. This NIOSH CIB, based on NIOSH’s assessment of  the current available scientific information about this widely used material, 1)  reviews the animal and human data relevant to assessing the carcinogenicity and  other adverse health effects of TiO2; 2) provides  a quantitative risk assessment using dose-response information from the rat and  human lung dosimetry modeling and recommended occupational exposure limits for  fine and ultrafine (including engineered nanoscale) TiO2; and 3) describes exposure monitoring techniques,  exposure control strategies, and research needs. NIOSH recommendations are nonbinding, and should therefore be  listed under the voluntary initiatives. However, they can be seen as an initial  step to mandatory regulation enacted by OSHA, which is why CIB 63 was considered  a landmark in nanotechnology regulation.

French code de l’environnement, Livre V, Titre II,  Chapitre III, (articles l523-1 to l523-5). According to this text, manufacturers, importers  or distributers of nanoparticulates must inform relevant authorities, and  provide information about the substances involved. The information relates to  intended use of substance, quantities involved, identity of the professional  users, and danger relative to exposure in terms of health or of environmental  risks. The data provided can be made available to the public.

The code states  that national interest may lead to a request to opt out of REACH regulation. Auplat concludes that there is currently no strong backbone to  global nanotechnology policy making. “On the one hand, there are various pieces  of regulation which are disconnected and seem to emerge more or less in an ad  hoc way. On the other hand, at the international level, the position of large  international organizations like the EU is not stable: they have until now not  favoured specific regulation of nanotechnologies considering that existing  frameworks were sufficient, and they seem to be changing their minds.”

By Michael Berger. Copyright © Nanowerk

Read more: http://www.nanowerk.com/spotlight/spotid=29822.php#.UVxq-YcGT50.twitter#ixzz2PW0a2l1u

Pfizer inks deal with nanotechnology drugmaker


QDOTS imagesCAKXSY1K 8CAMBRIDGE, Mass. (AP)BIND Therapeutics said Wednesday that Pfizer Inc. has agreed to pay at least $160 million per drug as part of a collaboration to develop targeted medicines using nanotechnology which use particles measured in billionths of a meter.

BIND is developing an experimental group of targeted, programmable medicines called Accurins to treat cancer, heart disease and inflammatory disorders. The privately held company’s technology comes from two laboratories that specialize in nanotechnology at Harvard Medical School and the Massachusetts Institute of Technology.

Pfizer will make initial payments of roughly $50 million, plus $160 million in regulatory and milestone payments for each targeted drug, according to an announcement from BIND.

Both companies will work on early-stage research for the drugs, and Pfizer will have the exclusive option to develop and market any products produced from the collaboration.

BIND has one product in early-stage clinical testing called Bind-014, a targeted Accurin that contains the chemotherapy drug docetaxel. The product is designed to attach itself to a protein that is expressed in some cancer cells and new blood vessels that feed tumors.

In an unrelated announcement Wednesday, the Children’s Hospital of Philadelphia said it will collaborate with Pfizer on therapies for children. Pfizer has research relationships with 21 academic hospitals throughout the U.S. with the aim of developing new products.end of story marker

Guiding stem cell migration to heal wounds


QDOTS imagesCAKXSY1K 8Healing cells migrate toward injured tissue not unlike how animals carry out their annual migrations – which is to say that it’s all a bit of a mystery. Grantees at UC Davis are working to clear up at least some of the mystery as a first step in learning to how guide stem cells to where they are needed.

 

There’s some evidence that wounds disrupt normal electric currents, and that cells can navigate toward that disruptions. Min Zhao and his colleagues at UC Davis have been studying how the cells detect this current and migrate accordingly. A press release about their work, published in the April 8 issue of Current Biology, quotes Zhao:

“We know that cells can respond to a weak electrical field, but we don’t know how they sense it. If we can understand the process better, we can make wound healing and tissue regeneration more effective.

They went on to give this inspired description of how cells move:

Think of a cell as a blob of fluid and protein gel wrapped in a membrane. Cells crawl along surfaces by sliding and ratcheting protein fibers inside the cell past each other, advancing the leading edge of the cell while withdrawing the trailing edge.

Essentially, all those ratcheting and sliding fibers seem to respond to the electric signal, drawing the cell toward the negative electrode.
In his Basic Biology award, which funded this work, Zhao says he hopes to optimize the type of current needed to direct the migration of stem cells to sites where they are needed. He recently filmed an Elevator Pitch with us, describing how his work could be used to guide stem cells toward a brain region damaged by stroke.

Watch the video on YouTube Here: http://www.youtube.com/watch?v=GwZ_ruVKfGk&feature=share&list=PLIeX9Lq8O-wHxcx3CleSdE5yuqUkm9Ogw