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Individual boron and nitrogen atoms are clearly distinguished by their intensity in this Z-contrast STEM image. Each single hexagonal ring of the boron-nitrogen structure consists of three brighter nitrogen atoms and three darker boron atoms. The lower (b) image is corrected for distortion. (Credit: ORNL.)

According to a press release, using a special Z-contrast scanning transmission electron microscope, researchers at Oak Ridge National Laboratory took the first picture detailed enough to differentiate different atoms within a chemical compound. This super-high resolution scanning may play an important role in the future of materials chemistry, where tiny atomic differences can have profound effects on the properties of different chemical compounds.

This is not the first picture of an atom, nor is it the first picture of atoms from different elements. However, in those older photos, the atoms were arranged beforehand by scientists. But in the Oak Ridge pic, the material was created chemically, and the picture was still able to identify individual atoms.

“This research marks the first instance in which every atom in a significant part of a non-periodic material has been imaged and chemically identified,” says Materials Science and Technology Division researcher Stephen Pennycook. “It represents another accomplishment of the combined technologies of Z-contrast STEM and aberration correction.”

The material in the photo, boron nitride, consists of boron, nitrogen, and oxygen, with some carbon atoms inserted in place of boron to serve as a control in the image. The STEM that took the picture used a 60 kilovolt beam. That’s a very low energy for this kind of microscope, because if the beam were any more powerful, it would displace some of the atoms in the compound.

Right now, scientists can only determine the chemical arrangements in a material through chemistry. By developing a technique for taking pictures like this, material chemists and engineers of the future will be able to simple look at the chemical compound to see its geometry and composition.

The team’s Z-contrast STEM analysis is described in an article published today in the journal Nature.

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Scientists at MIT, Intel and other facilities are researching microstructures in hopes of replacing lithium-ion batteries with nanoscale ultrapowerful capacitors. If successful, the new materials could be mass produced in volumes to power systems ranging from mobile devices to electric vehicles to smart grid storage units.

According to EE Times, Intel researchers have been working on “ultracapacitors with a greater energy density than today’s lithium batteries.” Intel is looking into producing these nanoscale ultracapacitors in high-volume manufacturing.

“It’s way too early to announce any results, but we are taking what we think is a fresh look at building ultracapacitors using our expertise in nanomaterials fabrication and high volume manufacturing,”says Intel lab director Tomm Aldridge.

MIT’s Laboratory for Manufacturing and Productivity is working on a multitude of micro- and nano-scale manufacturing techniques. For example, researchers at the Precision Compliant Systems Laboratory at MIT are looking into multi-axis nanopositioning systems.

The PCSL describes nanopostitioners as “electromechanical systems that position and orient components with [nanometer]-level accuracy.” While not directly related to the manufacture of nanoscale ultracapacitors, this technology may be able to include Intel’s nano-scale ultracapacitors on smaller-scale circuit boards, making electronics smaller.

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Here at CTT we write a lot about solar panel production and implementation, but have you ever wondered how solar panels are actually manufactured? Yet another great episode of Science Channel’s How It’s Made shows exactly what goes into the manufacturing of photovoltaic panels. (FYI, tomorrow’s episode is about hot dogs. Tune in at your own risk.)

Run time: 4:36

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According to the Chattanooga Times Free Press, Oak Ridge National Laboratory is working on a chemical process to separate highly radioactive spent fuel to recover unused energy. The process is referred to as nuclear waste recycling, and although recycling nuclear fuel might seem like a no-brainer, virtually all commercial nuclear power plants in the U.S. use a once-and-done “once through” system.

“Recycling the waste is a better strategy than storing it,” Sherrell Greene, director of ORNL’s nuclear technology programs, says, noting that 90 percent of the spent fuel’s energy remains in what now is treated as highly radioactive waste. (The reason for not using more of the fuel is that radioactivity also causes changes to the fuel rods and the formation of materials that contaminate the process and reduce efficiency.

Some nuclear reprocessing technologies have been used in France, Japan and Russia, but they have been rejected several times in the United States over the past three decades.

Researchers are hoping to develop a method to extract the usable portion of the spent fuel without the inherent security risks of isolating plutonium.

Current reprocessing leaves behind highly poisonous nuclear waste. This waste, however, degrades in tens of years instead of tens of thousands of years, which makes the need for very long-term storage less acute, experts say.

Researchers, however, also say they are trying to scale up techniques to transmute radioactive elements with long half-lives to ones with much shorter ones.

For more information on this topic, see John Marra’s excellent video, “A New Paradigm for Nuclear Waste Management.”

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Credit: RavenBrick

Last week I had a post about Sage Electrochromics and the company’s line of smart windows. But, there is another company, RavenBrick, that says it has a less expensive, film-based approach to smart glass: smart windows (and smart walls) that offer many of the same features without needing any of the wiring required by windows like Sage’s.

RavenBrick says its special film can quickly turn a window opaque – at a preset point – just by using the sun itself. So, let’s say you have a house or building where it would be useful to have sunlight warming the interior when it is colder outside, but where it would also be convenient to block the sunlight on hot days. RavenBrick says it can make a film, preferably used between panes in a single insulating glass unit, that can do that. The film is clear in the IGU at a low temperature but the material in the film goes through a phase change and turns opaque at a higher temperature.

That ability is pretty intriguing by itself. But there are several more important things to note about the company’s film. RavenBrick says the film can be customized and fine-tuned along several important technical and aesthetic parameters. For example, the opacity can come two different ways: by darkening or by whitening. In the former case, the phase changes causes the film to block most of the light and, in the latter case, the phase change instead causes the film to diffuse the light.

One of the film’s creators, Wil McCarthy, wouldn’t reveal what’s in the film, even in general terms (patents pending), other than to say that it was a “nanostructured optical material.” But he told me that the film could be customized along several parameters including what temperature the phase change occurs, what portion of the light spectrum is blocked, what level of diffusivity is desired, etc.

McCarthy, who helped launch RavenBrick, says its technically possible to adjust the temperature change point to a precision of 0.1°C, but for practical purposes he said it makes more sense to develop a commercial product that would be set to change at just one “sweet spot,” such as 80°F, or perhaps offer products customized to a few particular geographic regions.

The company calls an IGU that uses its darkening film a RavenWindow. A RavenWindow would still allow some light transmission - about 5%. McCarthy said the effect is like putting a pair of sunglasses: the change happens quickly, but still allows a useful view from the interior.

An IGU that uses the whitening film is dubbed a RavenLight, and may be more practical in, say, skylight situations where the presence of diffused light is more important than a clear view.

Still another version of the film could turn a window into a mirror with 95% reflectivity.

Of interest to DIYers, the company literature notes that these films could be used in post-construction applications. But McCarthy told me that slapping the film on an existing window would not be as efficient as sealing the film in a double-paned IGU.

RavenBrick has one more major trick up its sleeve: it’s RavenSkin Smart Wall System. Think of it as a thermal battery. McCarthy says its possible to build an entire wall, composed of basically the same reversible phase-change material used in the window film, that would absorb sunlight and other ambient thermal energy during the day, and then gradually release heat in the evening. The wall, for example, could be constructed of material that would gradually reverse a sun-induced phase change and release its heat energy at, say, 72°F.

RavenBrick is a small company still in its start-up phase. Its core technology is this customizable phase-changing material. McCarthy and others at the company often use the term “programmable matter” and say the film is just one example.

Programmable matter is something that McCarthy has been thinking about for some time. Some of his work is conceptual (science fiction stories) and some technical (he has gained several related patents, e.g., one on the use of “programmable dopant inside bulk materials, as a building block for new materials with unique properties”).

Once an aerospace engineer working for a NASA contractor, McCarthy is now focused on making the RavenBrick a success. Besides not needing electrical connections for his company’s products, McCarthy bristles at comparisons to Sage and similar companies. He acknowledges that his smart windows don’t come with the convenience of a light switch, but he notes that two big differences, cost and scalability, favor RavenBrick’s approach. McCarthy says RavenWindow film can be manufactured cheaply, even at the current size limit of 1.3 m², for what would be an MSRP of $25 per ft² with a six-year payback period. Standard film-making technology could easily ramp the size up to several meters X infinity and would drive the MSRP to only a few dollars per ft².

From a business strategy point of view, McCarthy says the biggest difference is that RavenBrick, unlike Sage, “is not interested in making its own windows or competing with the big players in the window industry.” It is only interested in making or licensing the film to the window makers, and providing other R&D services.

Testing of RavenBrick products is underway. McCarthy said ASTM testing has been underway for some time: Three of the four ASTM tests have been successfully completed, the last test is underway and McCarthy is hopeful that a 30-year lifespan will be certified.

He also said the National Renewable Energy Laboratory (NREL) would be installing and testing the windows this summer in some of the lab’s executive offices.

Stay tuned. RavenBrick’s films might fly onto our windows in the next few years.

Here is a short video on RavenBrick:

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