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Researchers have used the recoil of bubbles to mix coolant around microelectronics:
The bubbles that form on a heated surface create a tiny recoil when they leave it, like the kick from a gun firing blanks. Now researchers at the University of Illinois at Chicago, under funding from NASA, have shown how this miniscule force can be harnessed to mix liquid coolant around high-power microelectronics — in space or on Earth. [...] "In flights to Mars or the moon, equipment like computers generate a lot of heat," Yarin said. As the computers and chips become smaller and are packed tighter, the production of heat becomes a restriction on computing power.
Engineers have looked to "pool-boiling," which is liquid-cooling at a temperature near the boiling point of the fluid. In boiling, all heat is absorbed in converting the liquid to vapor, with no further rise in temperature until the phase change is complete. But the lack of gravity in space poses a special problem for pool-boiling: The bubbles have no buoyancy.
[...] Yarin and his coworkers sandwiched two heat-generating circuit chips back-to-back. By alternating the voltage to the two chips, they were able to cause the apparatus to swing back and forth through the coolant at about 1 centimeter per second. "When one chip operates, it produces bubbles and a recoil force. Then the other, and it pushes back — enough to swing the chips in the cooling fluid and shed the bubbles," Yarin said. "It works with or without gravity – in space, exactly as on Earth."
Swing-like pool boiling on nano-textured surfaces for microgravity applications related to cooling of high-power microelectronics (open, DOI: 10.1038/s41526-017-0014-z) (DX)
(Score: 1, Disagree) by qzm on Tuesday March 07 2017, @07:57PM (5 children)
Just pump the fluid over the chips.
I know..I know.. far too simple and practical. Currently common practice. Too easy to have backup pumps, etc.
No.. Having chips swinging through a solution under bubble power send like a much better idea.
Sigh.
(Score: 3, Interesting) by Unixnut on Tuesday March 07 2017, @08:08PM (2 children)
I can think of a few reasons not to just "pump the fluid over the chips"
1) you need pumps, something with moving parts, which can fail in space. Yes, you can have multiple pumps for redundancy, but still. How many pumps can reliably work in temps near absolute zero, and for how long? Not to mention the weight of all the extra pumps, and heaters to prevent freezing.
2).Leaks. It would suck if everything works, but in the vaccum of space the fluid leaks out somewhere between the chip blocks, the pumps and radiator. This can be solved by building closed units, but that adds weight and complexity.
3) weight. Seriously, sending stuff to space is stupidly expensive. You want things to be as light as possible.
4) power draw. In addition to the chips, you have to spec out more power to drive the pumps, heaters, etc.... which takes precious power from scientific instruments or comms.
This concept of theirs has no moving parts (apart from the fluid), so in theory should be much more reliable (and lighter) than pumping the fluid around. Plus the motive force is done by shunting power between two chips, which you would already have with you for redundancy (so re-using existing hardware, hence saving weight).
In fact, the more I think about it, the more it appears as a very elegant and ingenious solution. Cheap (no extra subsystems), light (only uses existing subsystems, minus the fluid weight), solid state (so should run much longer without maintenance), resistant to cold temps (The chips are heating the fluid by virtue of how it works), and no extra power needed (you are using the power for useful computation, and the heat would be wasted otherwise).
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @09:07PM
"This concept of theirs has no moving parts (apart from the fluid), "
Actually, it sounds like they're turning the whole circuit into a moving part that depends on its motion not to overheat...
(Score: 2) by butthurt on Tuesday March 07 2017, @10:09PM
> you need pumps, something with moving parts, which can fail in space.
"Ferrofluid pump has no moving parts"
http://physicsworld.com/cws/article/news/2011/sep/26/ferrofluid-pump-has-no-moving-parts [physicsworld.com]
The thermal cycling of the chips sounds like something that could cause them to fail early.
(Score: 1, Interesting) by Anonymous Coward on Tuesday March 07 2017, @10:08PM (1 child)
In so many processes, heat is considered to be "waste".
Here, it is being put to use.
Every human needs to reconsider "waste".
We all need to think of the "unusable" output of one process as an input to another process.
Imagine industries that are located/arranged such that the "pollution" from the first would flow into the next plant as raw materials and the second's "waste" would pass on to the next plant in line to be used to produce that operation's product.
Imagine a ring of such plants such that the unwanted byproducts of the "last" plant would flow back into the "first" to be used there.
On a related topic, Sweden does the reduce/reuse/recycle thing so well that they have recently run out of "trash" to burn in order to create electricity/heat.
They've had to import other countries' "trash"--and are making a nice little profit doing that.
In northern Europe, they also have laws that say that stuff has to be built such that at the end of its life it can be easily disassembled, making the components readily available to be reused/recycled.
-- OriginalOwner_ [soylentnews.org]
(Score: 0) by Anonymous Coward on Wednesday March 08 2017, @02:03AM
If Sweden didn't import other countries' "trash" it wouldn't have so many rapes.