Steam age tech takes heat off chips

Victorian engineering has come to the aid of overheated twenty-first century chips

One of the key discoveries in steam engine technology was that multiple small pipes in the boiler extracted heat far more efficiently than a single pipe. Now Californian company Cooligy is applying a similar idea to cooling high performance chips, and a quadrupling in heat-shifting performance is promised.

Cooligy has announced its Active Micro-Channel Cooling System, aimed squarely at the next generation of high-speed processors. Claiming a maximum heat removal capacity of 1000 watts per square centimetre -- the existing limit is around 250 watts for passive systems -- Cooligy says that the system is particularly good at cooling hot spots on the chip, which will get smaller, hotter and more common as designs go to 90nm and 65nm.

The system has two innovative parts: a sheet of silicon with hundreds of microscopic channels etched into it, and an electrokinetic micropump. The silicon fits over the top of a microprocessor or other chip and the channels are filled with water. The electrokinetic micropump contains a porous bed through which water flows when a voltage is applied; ionic charges in the water push the liquid along. This is silent, and can easily develop high enough pressures to overcome the natural viscosity of water in very narrow passages.

After the water is pumped above the chip, passing a millimetre away from the active layers, it circulates through a radiator and releases the heat to the outside.

Based on technology initially developed at Stanford, the system has been developed in conjunction with companies such as Intel, Apple and AMD, the company says. Samples of the product are expected towards the end of the year, with prices in the region of $25 to $30.