Wednesday, June 21 2006 12:31 Hrs (IST) - World Time -

London: German researchers have developed an exotic form of silicon that can be stuck together and then peeled apart.

The material, dubbed 'silicon velcro', could be used to manufacture microprocessors and devices that manipulate fluids on microscopic scales, according to a report on the website of New Scientist.

Researchers at the Technical University of Ilmenau in Germany created the material from 'black silicon' which is generated when normal silicon is hit with a powerful laser beam or bombarded with high-energy ions, producing a dense, microscopic array of needle-like structures on its surface.

The researchers used high-energy ions to generate black silicon bristling with around 1 million needles per sq mm and each needle is about 15 to 25 micrometers in length.

They found that two surfaces covered with the material adhere when pressed together. Microscope analysis shows this is because the needles on each surface jam in between one another under pressure.

According to the research team, silicon Velcro could prove useful for microchip manufacturers, helping engineers manipulate very thin layers of silicon without using heat or adhesives, which can damage components.

The researchers also used the material to create devices that control the flow of fluids on microscopic scales for chemical sensing and analysis.

These devices are made by sticking together a layer covered with tiny grooves and another, smooth layer and the layers of silicon Velcro can be unstuck afterwards to retrieve a valuable substance or examine what has happened inside, they said.

Silicon Velcro can be used more than once, maybe three or four times, but not indefinitely, the researchers said.