Molecular chip promises much

Researchers at the Hewlett-Packard research labs have turned to nanotechnology to help create a system that can store at least 10 times as many bits as existing silicon memory.

The team have created a working prototype mini-memory that is barely one micron square. More than 1000 of these prototypes would fit on the tip of a human hair.

The researchers said the memory chips could be manufactured quickly and cheaply.

Small print

Nanotechnology is the science of working on almost the smallest of scales, one nanometre is a billionth of a metre.

The seven-strong team at Hewlett-Packard made the miniature memory by first laying down eight parallel platinum wires, each one of which was only 40 nanometres across.

A layer of conductive molecules was put on top of this and then another eight wires were laid across the top at 90° to the base wires.

A memory bit was created at the 64 points where the wires met and trapped molecules.

By applying voltages to the wires the researchers were able to write and erase information in the memory bits.

Refined working devices could have memory capacities of 100 gigabits per square centimetre.

"We believe molecular electronics will push advances in future computer technology far beyond the limits of silicon," said R. Stanley Williams, HP Fellow and director of Quantum Science Research at HP labs.

Importantly the molecular memory created by the HP researchers remembers the information stored in it when its power source is switched off.

The creators of the mini-memory believe it should be possible to manufacture the devices relatively quickly and cheaply.

Hybrid electronics

The working prototype was created using a modified printing technique that used silicon moulds to create the platinum wires.

But the scientists also admit that they have a lot of work to do to refine their technique because the small size of the components makes the gadgets fragile.

Researchers are turning to nanotechnology because conventional ways of making computer memories and processors fall foul of fundamental laws of physics when individual components are below a certain size.

Experts believe that nanotechnology is likely to make its first working appearance in hybrid devices that combine traditional electronics with the tiny circuits.

The makers of portable consumer gadgets are likely to be attracted by the potentially vast memory capacity of devices built on such small scales.

"Capacity and performance could be extended enormously by layering molecular-switch devices on conventional silicon without the need for complex and expensive changes to the base technology," said HP researcher R Stanley Williams.