Published on April 1st, 2014 | By: Eileen De Guire0
Other materials stories that may be of interestPublished on April 1st, 2014 | By: Eileen De Guire
ARPA-E is accepting applications for Fellows and Technology-to-Market Scholars. During their two-year tenure, ARPA-E Fellows identify breakthrough energy technologies and white spaces. During their 8-12 week tenure, ARPA-E Technology-to-Market Scholars conduct analysis and research to support the commercialization of ARPA-E’s high-impact energy technology projects and programs. Application requirements and instructions for both programs can be viewed in the Job Opportunities section of the ARPA-E website. The deadline to apply for Fellows positions is Friday, April 11. Technology-to-Market Scholars applications are due Friday, April 4.
University of Utah electrical engineers led byprofessor Massood Tabib-Azar fabricated the smallest plasma transistors that can withstand high temperatures and ionizing radiation found in a nuclear reactor. Such transistors someday might enable smartphones that take and collect medical X-rays on a battlefield, and devices to measure air quality in real time. The new devices designed by the University of Utah engineers are the smallest microscale plasma transistors to date. They measure 1 micron to 6 microns in length, or as much as 500 times smaller than current state-of-the-art microplasma devices, and operate at one-sixth the voltage. They also can operate at temperatures up to 1,450 degrees Fahrenheit. Unlike typical transistors, the Utah microplasma transistor “channel” is an air gap that conducts ions and electrons from the plasma once a voltage is applied. To achieve this unique design, the team etched away portions of the silicon film using a chemically reactive gas. This etching process leaves behind cavities and empty spaces to form the transistor’s channel and expose the gate underneath. The channel tested in this new study was 2 microns wide and 10 microns long, and helium was used as the plasma source.
By slowing and absorbing certain wavelengths of light, engineers open new possibilities in solar power, thermal energy recycling and stealth technology. More efficient photovoltaic cells. Improved radar and stealth technology. A new way to recycle waste heat generated by machines into energy. All may be possible due to breakthrough photonics research at the University at Buffalo. The work, published March 28 in the journal Scientific Reports, explores the use of a nanoscale microchip component called a “multilayered waveguide taper array” that improves the chip’s ability to trap and absorb light. Unlike current chips, the waveguide tapers (the thimble-shaped structures above) slow and ultimately absorb each frequency of light at different places vertically to catch a “rainbow” of wavelengths, or broadband light. Each multilayered waveguide taper is made of ultrathin layers of metal, semiconductors and/or insulators. The tapers absorb light in metal dielectric layer pairs, the so-called hyperbolic metamaterial. By adjusting the thickness of the layers and other geometric parameters, the tapers can be tuned to different frequencies including visible, near-infrared, mid-infrared, terahertz and microwaves.
Polymer materials are usually thermal insulators. But by harnessing an electropolymerization process to produce aligned arrays of polymer nanofibers, researchers have developed a thermal interface material able to conduct heat 20 times better than the original polymer. The modified material can reliably operate at temperatures of up to 200 degrees Celsius. The new thermal interface material could be used to draw heat away from electronic devices in servers, automobiles, high-brightness LEDs and certain mobile devices. The material is fabricated on heat sinks and heat spreaders and adheres well to devices, potentially avoiding the reliability challenges caused by differential expansion in other thermally-conducting materials.
Medical engineers have created a device the size of a bandaid that monitors patients by tracking their muscle activity before administering their medication. Methods for monitoring so-called “movement disorders” such as epilepsy and Parkinson’s disease have traditionally included video recordings or wearable devices, but these tend to be bulky and inflexible. The new gadget, which is worn on the skin, looks like a Band-Aid but uses nanotechnology to monitor the patients. Scientists have long hoped to create an unobtrusive device able to capture and store medical information as well as administer drugs in response to the data. This has proved difficult due to the large amount of onboard electronics and storage space required, high power consumption, and the lack of a mechanism for delivering medicine via the skin. Now, a team from South Korea and the United States have used nanomaterials to create a flexible and stretchable device that resembles an adhesive plaster, about one millimeter thick. The device comprises multiple layers of ultrathin nanomembranes and nanoparticles and is worn on the wrist. The recorded data then triggered the release of drugs stored inside the nanoparticleswith the aid of a wafer-thin internal heater.
An extremely tiny lensless camera, developed by Rambus, has been slowly making waves over the past year. Researchers for the company, David Stork and Patrick Gill won a Best Paper award at last year’s Sencomm 2013 for describing their new type of camera—one that might someday soon be used to give virtually any digital device, some degree of vision. The camera is both simple and complex, it’s really just a very tiny chip (CMOS imager) embedded in a piece of glass. Instead of a lens, a pattern is etched into the glass above the chip—the imager reads the light that is received, processes it using an algorithm developed by Rambus and converts it into a recognizable image. What’s amazing is that the etched pattern on the glass and the chip are both roughly the size of a period at the end of a sentence. Particular etched patterns allow for light to be intentionally refracted in different ways as it passes through the glass—images made from them would appear unrecognizable to the human eye, but the algorithm makes use of refraction properties to reconstruct the light received into a recognizable image.
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