As chips become smaller and more powerful, the question of how to cool them becomes imperative. IBM has developed a system of stacking chips one on top of another, as opposed to the more usual side by side, and with it a system for cooling the chips with water, using tiny arteries. Considering the chips themselves are just four cm. square but put together in a sandwich as IBM has done, they put out a kilowatt of heat, effective cooling is vital.
Thomas Brunschwiler at IBM’s Zurich Research Laboratory told the BBC:

