Did you know that your smartphone is really just a hand-held computer that enables you to make phone calls? And as a computer, its central processing unit (CPU) puts off a considerable amount of heat. Phone designers have to build cooling systems into their phones to prevent overheating that could lead to eventual failure.
With that said, it is possible that your smartphone has a water-based cooling system. That’s right, there may be a tiny amount of water flowing through your phone’s internal spaces. If you own a Samsung Galaxy Note9 or Galaxy S7 for example, you are carrying around a device kept cool with water.
It is all made possible by carbon fiber. The same material Boeing uses to make airplane wings and fuselage panels is utilized by Samsung to create closed-loop cooling structures for smartphones. It is all pretty fascinating when you learn how it all works.
Converting Water to Steam
A great Composites World article from digital editor Scott Francis explains what Samsung has done with some of its more recent models. At the heart of their cooling architecture is a carbon fiber system that circulates water deep in the bowels of the smartphone. That water picks up CPU heat, is converted to steam, then re-condenses back into liquid as it releases the heat and cools.
The system consists of a porous cooling surface and a series of tiny pipes. The cooling surface is known as a thermal spreader. Its job is to absorb heat being produced by the CPU. Water within the structure absorbs the heat and turns to steam. As the steam is forced through the pipes by pressure built up in the system, it releases the absorbed heat. That results in the condensation that returns the steam to liquid form.
Although the cooling system in your car is not a perfect example of what’s going on with your smartphone, it’s very similar. Both cooling systems rely on a liquid coolant to absorb heat, carry it away from its source, and disperse it elsewhere. Both systems are closed-loop systems that do not work very well if they spring leaks.
Why Carbon Fiber Was Chosen
You might wonder why Samsung chose carbon fiber as the material for their smartphone cooling system. According to Utah-based Rock West Composites, carbon fiber was the perfect choice. There are many reasons for this, but at the top of the list is tensile strength and durability.
Smartphone makers cannot afford to use a material that could spring a leak. That would obviously end up being the end of the smartphone. Carbon fiber is strong enough to last well beyond the life of the average smartphone with very low risk of failure. Simply put, smartphone makers do not have to worry about leaks when they use carbon fiber.
Next, carbon fiber does not absorb heat. It conducts heat across its entire surface, which means it helps to dissipate heat quickly and effectively. This is one of the key properties that makes carbon fiber so valuable as a material for smartphone cooling systems. It just performs so well.
Finally, carbon fiber is very easy to fabricate into tiny parts that might prove challenging for other materials. Fabricators can make some impressively small parts perfect for the confined spaces of the smartphone case. As an added bonus, carbon fiber is lighter than other materials as well. A carbon fiber cooling system does not add much weight, which is important to phone makers looking to control both weight and size.
And now you know.
