Press releases
Please quote Nature Materials as the source of these items.
June 2008
Microstructures stay on track
A technique for the self-assembly of polymeric microstructures, which works by using a guiding 'rail' mechanism, is reported online this week in Nature Materials. The method could be used for manufacturing two-dimensional patterns of living cells for tissue engineering and manipulating silicon devices for microchip packaging.
On the micrometre scale, conventional assembly techniques such as robotics are often not applicable, and can result in errors in the final product. Sunghoon Kwon and colleagues devised a way to guide the assembly of microstructures within microfluidic channels, and make complex structures composed of more than 50 individual ones. All the microstructures used at the start of the process are incorporated in the product and different shapes can also be guided to specific locations, allowing the construction of two-dimensional representations of, for example, the Eiffel Tower, a Greek temple and a computer keyboard.
The method works by introducing a groove or 'rail' into the top surface of the channels and a complementary shape in the polymeric microstructure. In contrast to other fluidic assembly routes, the structures are guided along the rail rather than moving in the exact direction of fluid flow in the channel.
Guided and fluidic self-assembly of microstructures using railed microfluidic channels
Su Eun Chung, Wook Park, Sunghwan Shin, Seung Ah Lee & Sunghoon Kwon
Published online: 15 June 2008 | doi 10.1038/nmat2208
The unexpected metal
Placing two different organic insulators in contact creates a metallic channel at the interface, resulting in the formation of new electronic states, reports a study online this week in Nature Materials. These electronic states are not achievable in the bulk material and provide new ways of researching organic electronics.
Alberto Morpurgo and colleagues used a simple technique to bring the organic crystals known as TTF and TCNQ in direct mechanical contact. These crystals are very good insulators, but when placed next to each other, electrons from TTF can transfer to TCNQ thus creating a population of mobile electronic charges.
As Jochen Mannhart discusses in a linked News & Views article, these results promise new routes for research in organic electronics.
