Scientists have created a computer that uses tiny bubbles instead of electricity to make calculations:
The "microfluidic" computer performs calculation by squeezing bubbles through tiny channels etched into a chip. It can perform all of the logical operations needed to make a general-purpose computer.
In practise, such a computer would be much bigger than a PC and about a thousand times slower. Nevertheless, the bubble-based computer could lead to improved microfluidic technology for chemical analysis, say its designers.
Manu Prakash and Neil Gershenfeld of the MIT Center for Bits and Atoms in Massachusetts, US, created the devices by etching channels about 1 micron wide into silicon. They used nitrogen bubbles contained in water to represent bits of information flowing through these channels.
The channels are designed to carry out basic Boolean logic functions. These take simple variables and produce output based on a basic set of rules. The channels can also store binary information in the form of bubbles trapped in one of two connected cavities. The same principles are used to process complex information in electronic circuits.