SCIENTISTS have created the tiniest drop of water and the smallest object ever made in their quest to build a new generation of miniature machines. The discipline, called nano-engineering, involves objects a few tens of nanometres across - a thousand times smaller than the width of a human hair.
'This is engineering at its limit, where we are fabricating and measuring individual atoms and groups of atoms,' George Whitesides, from the chemistry department of Harvard University, told the meeting.
His group had made droplets each holding just 10 trillionths of a litre of water - roughly equal to the fluid content of a biological cell. 'No one has ever seen these before . . . they could become the basis of tiny reactors.'
Raymond Ashoori, from the Massachusetts Institute of Technology, said he had made 'an atom in a box', to which he could add electrons one at a time. The beauty of these 'artificial atoms' over real ones was that they could be made any size, and could be squashed more easily to see how they behaved.
Professor Whitesides told the meeting that the work should lead to a new class of electronic devices, or at least make it easier to build smaller versions of today's electronic components, such as microprocessors for ultra-dense, ultra-fast computation.
The dimensions of the objects in nano-engineering are roughly the same as those of the internal machinery of biological cells.
Optimists have talked about the prospect of building minute machines that doctors could inject into people's arteries to spot and scrape away plaques built up on their surfaces. But Professor Whitesides was sceptical. 'That's what we have enzymes inside us for,' he said.