A designer of advanced cooling technologies – nanoCoolers – recently said that it would not commercially produce its liquid-metal cooling solutions introduced earlier in 2006. Instead, the firm will concentrate on the so-called thin-film thermoelectric solutions. A product introduced this year that was to feature liquid-metal cooler – a graphics card by Sapphire Technology – is currently put on hold and it is unlikely to be released commercially.

“We are excited about Thin Film Thermoelectrics (TF TEC) and therefore have refocused liquid-metal resources to TF TEC and have put new development of liquid metal based products on a lower priority,” a statement by the company reads.

The liquid-metal cooling technology is based on liquid metal cooling loops that contain a patented fluid called liquid-metal. Since the metal is electrically conductive, an electromagnetic pump is used to propel the liquid within a loop rather quickly. The liquid-metal loops act as typical heat-pipes: they rapidly and efficiently transfer heat from a heat-source to a radiator which is cooled-down either actively or passively. Currently Sapphire Technologies has working samples of its Blizzard product, but cannot manufacture them commercially.

“The liquid metal prototypes have achieved the desired target performance that is exciting to our partners and the market. Since we are not aggressively seeking new business with this technology at the moment we have removed the liquid metal information from our site at this time,” nanoCoolers said.

Thermoelectrics are solid-state devices based on semiconductor materials that take advantage of the Peltier effect to cool. At room temperature, most thermoelectrics are based on n-doped and p-doped Bismuth-Telluride semiconductor materials. When current flows from the n-doped material to the p-doped material, heat is absorbed. When current flows from the p-doped material to the n-doped material, heat is dissipated. By constructing a device where the current flows from n-doped to p-doped on one side and from p-doped to n-doped on the other side, one side of the device will absorb heat (get cold) while the other side dissipates heat when DC current is applied. By reversing the direction of the current, the hot and cold sides can swap polarities (the hot side becomes the cold side and vice versa).

In order to scale down size and increase cooling densities, nanoCoolers has developed a proprietary wafer-scale manufacturing process to allow the thermoelectric to be built using thin-film materials. This allows the length of the thermoelectric element to be scaled from millimeters down to microns, which lets significant improvement in cooling density and significant reduction in thermoelectric form factor. According to the company, its thin-film thermoelectric pad of 0.5cmІ surface size can cool down a device with 70W thermal envelope.

“We have garnered great results with our liquid metal products and believe we will have similar success with our TF TEC,” the company added.