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| Tiny Etch-a-Sketch |
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4 March 2008, for Technology Review It may be the world's tiniest Etch-a-Sketch. Researchers have demonstrated a new technique that could be used to create rewritable logic circuits and denser computer memory. Using an atomic force microscope (AFM), the researchers were able to draw nano-sized wires and dots that could be repeatedly erased and written.Led by Jeremy Levy of the University of Pittsburgh, the researchers used an AFM tip like a pencil, drawing electrically conductive paths--which act like metallic wires--on a special material. The lines were as thin as three nanometers, making them considerably narrower than the lines that can be drawn using electron beam lithography--one of the most precise techniques for etching devices out of silicon. The researchers used a two-layer material developed by Jochen Mannhart's group at the University of Ausberg, in Germany. The base is made of a strontium titanate crystal, with a thin layer of lanthanum aluminate on top. The interface between the two materials can be switched from insulating to conducting by applying a voltage across the interface. Levy and Mannhart's groups collaborated on a project to draw fine conductive lines at the interface by probing the surface of the material with an AFM, which has a nanoscale tip that can apply a voltage across a small area. The lines the groups drew were both fine and long; their length was limited only by how far the AFM tip would scan.... Click here to the rest of the article on the Technology Review website. |