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Nanotech

Flexible biocompatible LEDs for next gen biomedicine

Researchers from the University of Illinois at Urbana-Champaign have created bio-compatible LED arrays that can bend, stretch, and even be implanted under the skin. You can see an example of this in the image as LEDs have been embedded under an animal's skin.
While getting a glowing tattoo would be awesome, the arrays are actually intended for activating drugs, monitoring medical conditions, or performing other biomedical tasks within the body. Down the road, however, they could also be incorporated into consumer goods, robotics, or military/industrial applications.
Many groups have been trying to produce flexible electronic circuits, most of those incorporating new materials such as carbon nanotubes combined with silicon. The U Illinois arrays, by contrast, use the traditional semiconductor gallium arsenide (GaAs) and conventional metals for diodes and detectors.
Last year, by stamping GaAs-based components onto a plastic film, Prof. John Rogers and his team were able to create the array’s underlying circuit. Recently, they added coiled interconnecting metal wires and electronic components, to create a mesh-like grid of LEDs and photodetectors. That array was added to a pre-stretched sheet of rubber, which was then itself encapsulated inside another piece of rubber, this one being bio-compatible and transparent.
The resulting device can be twisted or stretched in any direction, with the electronics remaining unaffected after being repeatedly stretched by up to 75 percent. The coiled wires, which spring back and forth like a telephone cord, are the secret to its flexibility.
Rogers and his associates are now working on commercializing their biocompatible flexible LED array via their startup company, mc10.
The research was recently published in the journal Nature Materials.

watching nanoparticles grow

I have spent a lot of time over the past decade-and-a-half talking about nanotech and nanoparticles. The often unexpected properties of these tiny specks of matter are give them applications in everything from synthetic antibodies to fuel cells to water filters and far beyond.
Recently, for the first time ever, scientists were able to watch the particles grow from their earliest stage of development. Given that the performance of nanoparticles is based on their structure, composition, and size, being able to see how they grow could lead to the development of better growing conditions, and thus better nanotechnology.
The research was carried out by a team of scientists from the Center for Nanoscale Materials, the Advanced Photon Source (both run by US Government's Argonne National Laboratory) and the High Pressure Synergetic Consortium (HPSynC).
The team used highly focused high-energy X-ray diffraction to observe the nanoparticles. Amongst other things, it was noted that the initial chemical reaction often occurred quite quickly, then continued to evolve over time.
“It’s been very difficult to watch these tiny particles be born and grow in the past because traditional techniques require that the sample be in a vacuum and many nanoparticles are grown in a metal-conducting liquid,” said study coauthor Wenge Yang. “We have not been able to see how different conditions affect the particles, much less understand how we can tweak the conditions to get a desired effect.”
HPSynC’s Russell Hemley added, “This study shows the promise of new techniques for probing crystal growth in real time. Our ultimate goal is to use these new methods to track chemical reactions as they occur under a variety of conditions, including variable pressures and temperatures, and to use that knowledge to design and make new materials for energy applications.”
The research was recently published in the journal NANOLetters.