On Thanksgiving Day 2008, the US Patent & Trademark Office published Apple’s patent application titled Liquid-cooled portable computer . Apple’s patent generally relates to heat-transfer techniques and more specifically to the use of liquid coolants to transport heat in future MacBooks. The new cooling systems may eventually, according to Apple, go beyond the laptop and into their other portables such as the iPhone, iPod touch or even a yet unseen gaming console. With Quad-core processors coming to market in the coming year, cooling systems are going to be paramount in keeping desktops, laptops and other devices cool.

Future MacBook Cooling System with an Active Heat-Transfer Mechanism

According to Apple’s patent documentation, there are two cooling system methodologies being presented in their current patent. The first, as noted in FIG. 1A below, utilizes an active heat-transfer mechanism whereby the liquid coolant includes two phases of matter (such as a liquid phase and a gaseous phase).

For example, the liquid coolant may include bubbles that include a gas. Therefore, in some embodiments nucleation of the bubbles and/or latent heat may be used to increase the heat-transfer coefficient of the liquid coolant. Furthermore, in some embodiments the liquid coolant includes metal particles to increase the heat-transfer coefficient of the liquid coolant.

An Alternate MacBook Cooling System with a Passive Heat Sink

In some embodiments, a computer system may thermally couple the liquid coolant to a passive heat sink (as opposed to an active heat-transfer mechanism as illustrated above). This is shown here in FIG. 5 illustrating an embodiment of a notebook computer (noted as system 500). In this computer system, pump 510 circulates the liquid coolant through or in contact with an aluminum plate 512. As illustrated in the computer system 500, the aluminum plate may be positioned behind a display of a portable computer. In this way, heat transferred by the liquid coolant to the aluminum plate (and thus, the external environment) is less noticeable to a user than when coupled to a bottom surface of the computer system.

Apple lists Ali as the sole inventor of this patent.

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Written and researched by Jack Purcher.