
Fluidics - wglb
https://en.wikipedia.org/wiki/Fluidics
======
simonebrunozzi
"Fluidics, or fluidic logic, is the use of a fluid to perform analog or
digital operations similar to those performed with electronics."

Not sure why this is on the front page of HN. I find it mildly interesting,
but it's a wikipedia page and there's no relevance to recent facts or
discussions.

Anybody could help me understand?

~~~
waiquoo
There was a post about a hydraulic computer here the other day, this looks
like further reading. Interestingly, there seems to be a slow increase in
intrest for ionotronics where logic is implemented using nanopores in salt
water, where current is carried by ions instead of electrons. Generally the
propogation delay is orders of magnitude longer than in electronic circuits,
but the parallel between fluidic computation and biological processing (as in
brains) is compelling. I was able to put together a few gates and oscillating
electrofluidic circuits using electrically addressable nanopores in my PhD
work, but others have more recently made complete circuits.

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RobertRoberts
I wonder if something like this [0] (looks like moving liquids without pumps
or power) would be possible to miniaturize this idea further? (maybe smaller
amounts of electricity like in the brain combined with this kind of tech)

The stuff I have seen tends to be large on a scale reminiscent of the very
first computers. (ie, large mechanical switches powered by solenoids or
spinning gears)

[0] [http://www.surnetics.com/](http://www.surnetics.com/)

~~~
whoisjuan
To be fair, miniaturization never has been a problem in the electronics
industry evolution. Nowadays you can have more than 4,000,000,000 transistors
in a 10nm chip and the lithographic process advances to produce these chips
tend to evolve into even further miniaturization and more transistors.

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Maybestring
Pretty sure this project is dead:
[http://groups.csail.mit.edu/cag/biostream/](http://groups.csail.mit.edu/cag/biostream/)

But it has some pretty neat examples, not doing computation, but a
programmable system for moving, storing, and mixing samples.

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beagle3
Modern electronics have an effective limit of ~100 deg Celsius, which makes
them unsuitable for some uses.

Fluidics are order of magnitude slower and larger, but proper material
selection can make them withstand very high temperatures.

~~~
gene-h
Fluidics have actually found useful applications at extreme temperatures.
Fluidic capillary pyrometers have been used to measure the temperature of
molten steel and here is an image of a fluidic afterburner fuel control
operating at temperature's so hot it's glowing[0]

[0][https://imgur.com/uwPSpR5](https://imgur.com/uwPSpR5) from Fluidics
Quarterly Volume 4 Number 2, page 54

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gene-h
Fluidics was a technology that was invented at the wrong time. It was invented
in the 1960s just as transistorized computers were becoming common. One can
only speculate on what the world would be like if fluidics was discovered say
in the 1800s. It could potentially be mass produced with technology of the
time. Right off the bat one might be able to attain switching speeds similar
to relay computers for complicated circuits, audio-frequency operation for
simple circuits, and analog computation at decent speeds. So we can get things
like adding machines, somewhat automated factories, autopilots, sound
amplifiers, gunnery computers, and what not. Of course, this alternate history
is unlikely, because some of the knowledge necessary to develop fluidics came
out of understanding airplane flight. The coanda effect, wherein a jet of
fluid tends to stay near walls which is useful for making bistable flip flops,
was discovered accidentally when testing a new airplane design[0]

Even though fluidics came out at the wrong time it did find some niche
applications in aerospace and factory process control because fluidics was
more reliable than similar electrical and electromechanical systems for a bit.
Fluidics not having any moving parts is fairly robust and is tolerant of high
temperatures, high shocks, high radiation, high magnetic fields, and more. The
concorde actually used fluidic components in one of it's nozzle control
systems at one point[1].

Because of fluidics inherent EMP resistance and acceleration resistance,
fluidics has been considered shockingly recently for use in anti-ballistic
missile guidance systems[2].

Fluidics still enjoys some niche applications today. Some HVAC and industrial
control systems supposedly use fluidics. One interesting current day
application of fluidics is kosher sound amplification[3]. Orthodox Judaism
prohibits electronic sound amplification on the sabbath because it constitutes
work. Using a speaker to produce sound constitutes labor because it creates a
sound that did not exist before from electricity. Fluidics is able to get
around this prohibition and can amplify sound in the range of human speech.

[0][http://www.thermofluids.co.uk/effect.php](http://www.thermofluids.co.uk/effect.php)
[1][http://www.dtic.mil/dtic/tr/fulltext/u2/a049256.pdf](http://www.dtic.mil/dtic/tr/fulltext/u2/a049256.pdf)
[2][http://www.dtic.mil/cgi-
bin/GetTRDoc?Location=U2&doc=GetTRDo...](http://www.dtic.mil/cgi-
bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA204334)
[3][http://acoustics.org/pressroom/httpdocs/132nd/2aaa8.html](http://acoustics.org/pressroom/httpdocs/132nd/2aaa8.html)

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wglb
I wonder if side-channel attacks are possible on fluidics.

~~~
jloughry
Sure. Any incidental effect related to the actual physics used to encode
information potentially could leak information. Fluid has mass, and
accelerations require forces, so acoustic, acceleration, and thermal side
channels are all a possibility.

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virgulino
That is awesome. Thanks!

