Scientists have developed an electron beam which can produce letters small enough to write a 29 volume encyclopedia on the head of a pin, it was reported recently.

An electron microscope at the University of Liverpool transmits a beam of highly charged sub-atomic particles capable of drilling millions of ultra-fine holes through certain materials, the Science and Engineering Research Council said.Cutting holes roughly the size of an atom in materials such as aluminum oxide could enable information to be stored at a density at least 1,000 times greater than in the latest computer storage device.

"It is possible to write one million lines side by side in the width of a pencil line, or to drill one million million holes on the head of a pin," the council said.

The precision needed would be like trying to paint the window frame of a doll's house on earth from a satellite 100 miles above the planet, using a single-bristle paint brush with a handle 100 miles long, it added.