[PEN-L:31521] computational glass

["Ian Murray" <seamus2001@xxxxxxxxx>]

Prototype glass sheet computer unveiled
18:28 22 October 02
NewScientist.com news service

A transparent computer processor has been printed on to a flat plate of
glass by researchers at Sharp's Japanese laboratory. Their success suggests
ultra-thin computers and televisions could in future be built entirely on a
single sheet of glass.

The prototype processor runs at a speed of 2.6 megahertz, making it basic by
modern computer standards. The latest desktop processors run about 1000
times faster, at 2.8 gigahertz.

But the prototype shows that complex electronics can be printed straight
onto glass with transparent silicon.

"We believe putting any Central Processing Unit onto glass, something that
had been impossible up until now, is epoch-making technology," said Sharp
spokesman Tetsuya Igarashi at a press conference in Japan.


Amorphous vs continuous

The pixels of liquid crystal displays are normally controlled using
amorphous silicon. This material is ideally suited because it is
transparent. But it is bad at conducting electrons because its internal
structure is irregular. Heating amorphous silicon increases its regularity,
but only to a limited degree.

The new "sheet computer" uses a relatively new material called continuous
grain silicon, developed by Sharp and Semiconductor Energy Laboratory, also
in Japan.

The crystal structure of this material is already aligned, meaning that it
naturally conducts electrons up to 600 times faster than amorphous silicon.
This means complex electronic components can be printed in this material.
Sharp says continuous grain silicon could eventually approach the efficiency
of the single crystal silicon used inside today's computer chips.

Sharp says the first consumer devices based continuous grain silicon should
be ready by 2005.