LM10 uses a special pump design made by coolant

Tag : melting metals

LM10 is an advanced prototype CPU cooler. The new cooler operates on fundamentally the same principle aswater cooling; a fluid cools the CPU, is itself heated in theprocess, and circulates back to the CPU through a radiator in whichthe fluid itself is cooled. This system, fundamentally the same,is used to cool everything from CPUs to cars to nuclear reactors,but the properties of specific implementations depend greatly onthe technical details. By changing two very important details,Danamics and its partner, Cyberdyne Systems, hope to make afundamental breakthrough in CPU cooling.

The working fluid in the LM10 is described as "liquidmetal," which is probably a Mimetic Polyalloy like Galinstan or its equivalent. Galinstan is a mixture in both name andcomposition of Gallium, Indium, and Tin. With a mixture ratiooptimized for low melting point (referred to in Chemistry as aEutectic mixture), it is liquid down to -19 degrees Celsius,preventing any problems with solid metal clogging the tubes. Itskey advantage over water is a very high thermal conductivity: somethirty times that of water, high even for metals, and a thermalcarrying capacity driven upward by its high density relative towater. Danamics refers to these advantages as "superior thermophysical properties," which probably has a much cooler ring inDanish or with a deep Austrian accent. Galinstan is much less toxicthan mercury, and favored for this reason, but is known to cause embrittlement problems .
Using Galinstan allows Danamics to use a novel approach to pumpingthis fluid around. While traditional water and other liquid coolingsystems for CPUs use mechanical pumps, which are loud, bulky,sometimes break down, and consume power, the use of a liquidcoolant which is a good conductor, as Galinstan is, allows Danamicsto employ a technology called electromagnetic pumping. A current isdriven through the working fluid, creating a magnetic field which,acting on the fluid, pushes it through the cooling loops. This kindof pumping system is used for pumping the liquid Sodium used incooling some nuclear reactors. It relies on the use of liquidmetal's conductive properties and is thoroughly impossible withwater. Danamics points out this new pumping technology"contains no moving parts, shafts, seals, etc., emits no noiseor vibration, has unlimited MTBF... suffers no performancedegrading over time," and if damaged can reassemble itselffrom its molten pieces and continue cooling. They also claim thatproprietary advances in "multi-string" pumping technologymean their pump will consume only one watt of electrical power topump the Galinstan through the coils of the LM-10. Mechanical pumpsconsume vastly more power; some PC liquid cooling kits are in the forty-watt range .
The electromagnetic pump moves the heat from the CPU into the finsof a metal heatsink, where it is carried away passively or byairflow from installable fans. Because the LM-10 is a circulationcooler, it can never cool a CPU below ambient temperatures, andthus will never be satisfactory to diehard enthusiasts, although itcan form knives and stabbing weapons. However, if the technologylives up to its promise, it could make CPU cooling simple,reliable, quiet, and high-performing: the Holy Grail of cooling andHTPC enthusiasts. Danamics claims the technology is extensible toservers and laptops, and say they plan other products to follow theLM-10. Unless there's something rotten in Denmark, this cooler, andothers like it, could change the face of CPU cooling for thebetter.