Physics tip sheet #39 - Nov...( 1) Ultra-dense data storage from ultra...)

Ultra-smooth diamond-like carbon can provide the nanometer-thin corrosion protection layer necessary for ultra-high density magnetic storage devices, report the authors of this paper. As magnetic hard drives increase in density, they need ever-thinner protective carbon films, which must be must be continuous, dense, and free of holes. Until now it was not known whether any material could meet these requirements. The authors demonstrate that the diamond-like carbon, known as tetrahedral amorphous carbon, has the needed smoothness. It could be useful for other applications as well, as it maintains its ultra-smoothness with increasing thickness, unlike other known materials, which get rougher as they get thicker. The paper also develops a theoretical model that shows that the material's extreme smoothness arises from the process of growing the films, in which heat from ions deposited on the surface dissipates, melting and flattening the surface.

Journal article: Available to journalists on request

2) Pond snail brains on a chip
R. Kaul, N. Syed, and P. Fromherz
Physical Review Letters (to appear)

Researchers have used live pond snail nerve cells to implement a basic element of neural memory on a semiconductor chip. The team isolated two neurons from a pond snail and placed them on a silicon chip. They electrically stimulated one cell with a microcapacitor on the chip and recorded the signal transmitted to the other neuron. Repeatedly stimulating the first cell increased the strength of the connection between the cells, just as neurons in the brain strengthen their connections as part of learning and memory formation. The chip may find uses in brain research and drug development, and may eventually lead to neurocomputers with living nerve cells or microchips that could be implanted in th
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Contact: David Harris
harris@aps.org
301-209-3238
American Physical Society
17-Nov-2003