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Ferrofluid display cell Bluetooth speaker (hackaday.io)
330 points by thunderbong on May 14, 2021 | hide | past | favorite | 63 comments



For anyone as fascinated with this substance as I am, here [0] is a YouTube video of someone making it 'from scratch'. It's a very detailed explanation, and includes some comparisons of the outcome VS commercial ferro fluids.

[0] https://m.youtube.com/watch?v=6L8yUY-doNc


NileRed is one of my favourite chemistry YouTubers, along with NurdRage. There's so much great content on his channels.


When I first saw many of his videos, I was like: "damn, this dude has access to all sorts of chemicals, radioactive stuff, I bet he lives in Texas or Mexico".

Then I learned that he lives in the same city as me.


When I originally found his channel I thought he might be too young to take any sort of seriously, but he handles being that young pretty well. There isn’t a lot of YouTube nonsense, or begging for subscribers, or jokes that for extremely flat. A model for others I think. Really well done.

Although... Explosions and Fire is peak YouTube Chemistry to me!


I would assume that certain amount of basic chemistry is still quite advanced for a non chemist.

If you would create a YouTube channel talking about basis programming language you would also attract plenty of people.

Nonetheless I don't want to lower the value or skill of him.

I'm entertained by it and can't judge his skills.

It still takes a lot to stand in front of a camera and doing what he does but still it could be that a chemist find it boring what he shows.


Young? He's 29? Were you mistaken or are you implying that 29 is pretty young to be creating self-aware youtube content.


He has videos dating 7 years back. I thought he looked young for what he was doing. Did not see him until quite a bit into the video and it was not what I expected. Really knowledgeable, a lot of equipment and a really good setup for someone so young. There is also the fact that there is no big source of income that I could easily spot.


I read it to infer that NileRed looks pretty young for his age, which I think is true.


There's an interactive exhibit in the lobby of the New York Hall of Science that lets you deform a blob of this shiny goo. It's a lot of fun.


Thought of exactly the same exhibit -- love that thing! Worth a stop into NYHS to play with it. I immediately wanted to make one and I'm psyched to see on HN. Evidently it originally had buttons to control the charge, then curators upgraded it with the more tactile wheel controllers.

https://www.sciartmagazine.com/spotlight-michael-flynn-and-f...


Won't the ferrofluid increase impedance and cause changed frequency response?


Great video!


Very cool project. There is a video of it in action[0] at the bottom. This is something that screams Kickstarter to me.

[0] https://www.youtube.com/watch?v=7a3JiGTE9sc


If it becomes a Kickstarter, I really hope the makers know what they are getting into. There is a lot between a prototype and mass production, and a lot of projects fail between the two.

Keeping it small scale, hand made on demand and high priced may be a safer option.


Tongue-in-cheek:

There is an incredible amount of work between the prototype and mass production. There is however not that much work between a prototype and a campaign video.

Which is all one needs…


Thank you. Video should have been embedded at the top of the website. Only a video can explain the value of the idea.


21st century lava lamp. In that, it 100% has the chance to become an iconic consumer product.


I experimented with making a clock using ferrofluid previously. I was inspired by this clock [0] but put off by the price tag.

Generally the main issues I found were that it degraded over time and I had real trouble with ferrofluid smearing on the container.

Will have to try again now!

[0]: https://www.thisiswhyimbroke.com/ferrofluid-clock/


This kind of reminds me of the Heptapod writing system from "Arrival". I wonder what contributes to the cost -- is it simply because it's unique, or are some of the materials expensive?


The article mentions "Because ferrofluid adheres well to glass, special treatments were required on the glass" but doesn't go into details


Could be treated with something like Repelcote:

https://uk.vwr.com/store/product/2994602/repelcote-vs-water-...

which coats the glass with a layer of silicone polymer.

Not entirely unlike some automotive silicone "waxes" which repel hydrous materials.

Or treatment of the glassware with the much more hazardous dimethyldichlorosilane (DMCS), which actually reacts strongly with the the glass surface at the molecular "sticky points" (which otherwise cause water to wet clean untreated glass and form a H2O film rather than bead up).

The DMCS is pretty rough and you need to handle it under a hood since it can give off more "smoke" consisting of pure HCL vapor sometimes when you open the bottle, compared to opening concentrated hydrochloric acid.

And it eats through the bottle's plastic closure every few years, so it's one of the ones that you need to keep an eye on and replace the cap as needed.

But you get some pretty slick glassware.


Huh. I wonder if the commercial one had the same issues, and the price tag was an intriguing way to put people off reporting bugs? :)


That is so cool

But 12 grand!? Wow.


They must read HN, because they've reduced it to the low, low price of only $8k now.


12 Canadian.


Amusingly I made a prototype of something similar 4 years ago during university: https://www.facebook.com/1764751847/videos/10202928199083698...

It was done to promote the use of Ferrofluid for DataVis rather than a consumer product.


Happy to collab, if anyone is interested feel free to reach out... matthewmf.com


I can't see the video, but if it's the same idea could you give some details on what you used as a suspension fluid and how you dealt with the smearing on the container?



Really cool. With something like this I can't help but imagine combining it with real time signal processing/filtering. Where the visualization can be attached clearly to different components of the music. A vocal filter, melody filter, etc etc. I'm always dissatisfied with how visualizers don't really cue off auditor-ily obvious parts of songs.


Nice! I assume that was just ferrofluid and water?


That's pretty awesome - it picks up on way more signal detail than the top project (which is also nonetheless cool).


Yeah, it does feel weirdly out of sync though.


Do you know how well it works if the speaker is on top of the bottle, pointed downward at the fluid?


> This is called ferrofluid. It is a material developed by NASA in the 1960s. It was used as both spacecraft fuel and sealing material.

I'm a bit curious how ferrofluid was used as a fuel.


It's commonly suspended in Kerosene, so maybe that's what they meant? Bit of a long stretch though.


This says it was an idea to pull rocket fuel to the right end of the tank without gravity

https://www.nasa.gov/feature/glenn/2021/history/novel-rocket...


I guess it would be easy to build a pump with it that has no moving parts.


Self cleaning and self lubricating as well as kerosene is a solvent and lubricant.


Ferrofluid is unstable iirc. I wonder how long this fluid lasts.


Ferrofluid is was used in disk drive motors to seal bearing grease from wandering out so it has reasonable life span of greater than 5 years from my experience


Reminds me a lot of Winamp that popularised such kind of music visualisations.


In the 90's and 2000's, car radios and the like had some really interesting visualizations going on. The market for radios and music installations that aren't high-end seems to have pretty much collapsed thanks to mp3 players and bluetooth speakers though. That said, there's still things like portable karaoke speakers that still come with the bells and whistles.


Funnily enough given your user name, Cthulu was a popular visualiser back in the DOS days of the 90s.

https://en.m.wikipedia.org/wiki/Cthugha_(software)

Edit: it was cthugha... my old brain is failing me :)


I really wish we were still there culturally.

Imagine the kind of music visualizers we could have with AI, CUDA cores, and RTX...


I want this, buy just as an eyeball that follows people around with its gaze


This is really cool. I hope someone makes a commercial version of it.


He can potentially do it, if he puts it on Indiegogo.


or he could go the traditional way and look for investors.

There are ups and downs to both


Naive question: could I use a speaker setup similar to this with my analog synth rig to use combinations of sine, saw, and square waves to find combinations of waves that suspended and manipulated this ferrofluid - and would those sound shapes have applications to laser pulses manipulating atoms? Intuitively, it seems like a way to model concepts for macro quantum computer.

While atoms may not behave as liquids, laser pulses are waves. Is there specific reason why not?


Yeah, you may find that due to the mass and length scale due to the viscosity/surface tension etc. would require sub audible frequencies. Totally worth trying. As far as atomic manipulation, no since that needs to be in a hard vacuum and low temperature. The same wave interference principle is used in that technology though.


That interference principle seems like a function of the size of the blobs and then how you manage the interference patterns of multiple oscilators. Mind you, if you can physically do it with audio synths, you can model it in software, which means we should be able to use ML via a GAN to grind through oscillator patterns to create the necessary pulse effect results.

Maybe more fun for a toy or a game.

This is a great video of the effect of sound on ferrofluids: https://www.youtube.com/watch?v=Axwm-5zng0s


I've always wanted to make something like this. I'm curious about parsing the fields into something both pleasing and physically representative of the actual waveform of the music. I'd also like to play around with using the fluid as a driver as well, though I'm sure getting sound out of it would be immensely difficult if not impossible without a horn the size of a barn. As far as I'm aware it has yet to be attempted.


I would be interested to see the ferrofluid dots resonating


Very neat. I wonder if there is some kind of soundpattern that can be used to 'sweep up' the smaller globules back into a single larger one.


Phenomenal. The concept, the design and the execution.


Oh, I thought the ferrofluid was going to be the speaker. Like plasma speakers [1].

The helium plasma speaker was only good for high frequencies, and needed something else for the bass. Using a heavy liquid for bass might work.

[1] http://hillplasmatronics.com/


Interesting the patent is from 1980.

Back in '74 I used to carpool with a grad student who had built an experimental pair which were already amazing.


Definitely the most creative use of ferrofluid I've seen for a long time. However I fear that long term you might have problems with the ferrofluid separating, emulsifying or oxidizing. It would be interesting if we got updates on how it holds up after a few weeks or months of use.


I guess if you made little cells with this fluid, you could make a matrix display.


this is the best DIY project I've seen, looks amazing


Great entry to xkcd 2326!


shutup and take my money. i want one yesterday!




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