Making Rheoscopic Fluid

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About: Hello, all! I am an avid tinkerer of all things. Follow me as I learn about all my interests!

Intro: Making Rheoscopic Fluid

Hello all,

I recently discovered rheoscopic fluid which is used to visualize the subtle currents in liquid. It works similar to dropping dye into the fluid to highlight currents, but rheoscopic fluid will never mix! Below is couple clips of my first batch.


 

Also, here is the video that started my pursuit:
https://www.youtube.com/watch?v=V98NnZsmTm4

How does this magical substance work? Well, to paraphrase Wikipedia, there are crystal flakes that align with the direction of shear when in motion. These aligned flakes reflect light toward the observer. Once the fluid stops moving, the flakes take on a random orientation and light is again diffused. Of course, Wikipedia gave no hint to the actual ingredient... I searched for a few good hours trying to figure out how this stuff works. Turns out it's something of a trade secret, it would seem...

...Next is some history I discovered during my quest for the secret, but you can skip to step 2 if you're dying for the details.

Step 1: History

Wikipedia was a dead end and also lacked any history on the fluid. However, I remembered the name of the video I saw was 'Kalliroscope' so I looked it up. The wiki article linked it to the works of an artist named Paul Matisse. After prolonged investigation, I was able to dig up only one photo of him and an amazing creation. He built a table with a large rotary disc of rheoscopic fluid. As you turn it, a blue hurricane like structure appears in the table. It also turned out that the kalliroscope in the video was produced by Matisse in a limited run and are quite valuable now.

Rheoscopic fluid was also used in the past by educators and engineers. These days computers are predominately used to run simulations of airfoils and fluid dynamics, but before that models had to be built and tested. One method was to take the object and submerse it in flowing rheoscopic fluid. I managed to find one video from the 1960's (@ 2:22 & 23:50 min mark) demonstrating flow instability:
https://www.youtube.com/watch?v=yutbmcO5g2o
A rare modern replica too:
https://www.youtube.com/watch?v=Pxdbdwf8pYA

But this form of art/science was largely lost after the 1960's. Only a few museums have displays and the limited places that sell rheoscopic fluid really don't say what it's made of.

Step 2: Secret Ingredients

After my long search, one video had 'mica powder' in the description. My wife was over my shoulder and said nonchalantly that it is used in makeup to give that sparkly appearance. It's also used in shampoo to give it that distinct shiny goo look. It's non-soluble with water which is why it doesn't mix. So I face-palmed myself for thinking it was some exotic substance and ordered white cosmetic mica powder from amazon: http://www.amazon.com/Shimmer-Powder-Cosmetic-Slice-Moon/dp/B008H3NJ4G/ref=sr_1_3?ie=UTF8&qid=1397076546&sr=8-3&keywords=mica+powder

You can also purchase different colors of mica. This opens up the possibility of, say, red mica against blue water. I chose white to begin with as it is very reflective and will appear to take on the color of the liquid.

It was only 1oz for $9, but it went WAY farther than I expected. You could use half an oz on a 10 gallon aquarium and have nearly the same results as Paul Matisse's table.

However, mica is not the only mundane source of rheoscopic fluid particulate. If you can acquire very fine aluminium powder, it will duplicate the mica's appearance pound for pound. You can even produce your own aluminum powder with a coffee bean grinder, foil and ear plugs. Inhalation and ingestion of the powder is dangerous though, and the grinder will only be good for aluminum. I won't rule it out though for future projects as it may be cheaper in the long run and a respirator/gloves will mitigate the danger. Video link: https://www.youtube.com/watch?v=phMgqT6EsYc

Yet another way is to use silver calligraphy ink. If you happen to have some, it's a good alternative. You can use an eye-dropper to transfer the ink out of it's bottle. If not on hand or at a nearby store, I would just order some mica powder.

Ultimately, the cosmetic mica powder seems to be the best bang-for-your-buck and requires little effort.

*Update* Finely ground graphite seems to show similar properties. It might be the cheapest of the bunch, but it's naturally dark appearance may be an issue. It should not be handled directly; use gloves and a mask or respirator just like the aluminum method.

As for the working fluid the powder is suspended in, I use ordinary water! It works fine even if it isn't what Matisse used. After examining the label on an original kalliroscope in ebay, I discovered he used Tetrachloroethylene. It's on the EPA's hot list and is a chlorofluorocarbon + solvent. User Starphire tells me that it was selected due to it's low boiling point. This allowed convection to be seen when the solution was heated. It's also not flammable like other low boiling point liquids, but it's toxic. However, the visual difference in motion is minuscule and you won't notice unless you heat it (plus water is cheap)!

Step 3: Ratios and Additives

I took 1/4 tsp of mica and mixed it with 1 liter of tap water! It yielded a very nice flow visualization and suspension of particulate. After several minutes it will settle to the bottom, but when you maintain even the slightest movement it will remain. Also, I think it's quite possible to use less powder to yield still impressive results. 1/8 tsp per liter didn't have quite the definition of currents as Paul Matisse's table or kalliroscope, but it's still was pretty nice.

Simply adding a drop or two of food coloring per liter will give you great colors without diminishing the effect. You don't want to make it too dark a shade or it may block out light from reaching down into fluid. If you do make a darker fluid, you will need to add more mica to offset the occluded water. You can see in the photos that the plain white mica shines very bright, but is can be clouded substantially with (red) food coloring if used liberally. I am working on a ratio for darker mixtures and will update if I succeed.

Have some neglected high-lighters around? You can use them to add a vibrant florescent glow. I used some needle-nose pliers to remove the end-cap of the high-lighter. This revealed the ink well, which is just a squishy cotton like cylinder. Squeezing the ink well over your bottle of water will cause drops of high-lighter to fall in (as photos show). It looks very bright just in ambient light, but that wasn't enough. I exposed the mix to a UV flashlight and it created an interesting effect. Instead of the mica shining near the surface, the fluid seemed to glow from within and blocked by the mica. In other words, it was inverted in appearance like a negative picture film. The comparison picture shows it somewhat, but doesn't really do it justice. **special thanks to users Gravityisweak and Rpotts2 for the idea**

User Bpark1000 suggested adding some rubbing alcohol or dish soap to the fluid. This will prevent anything from growing in your container over time. I've been putting some dish soap in mine to test and it seems to be none-the-worse for it. 

It's really that simple! Maybe it's just because of all research I had to do, but I expected it to be harder to get something this interesting.

*Note/Update: I tried using baby oil for a more viscous rheoscopic fluid and it didn't work. Oil based liquids seem to repel the mica powder. This causes it to form a layer between the jar and liquid. If you want to make the fluid more thick/viscous, you can mix in clear corn syrup to the water until you achieve the desired consistency. However, this seems to make the fluid really resist moving and makes for less spectacular results. Still, it retains a nice pearly shampoo like appearance and might be useful for something.

**Note/Update: Turns out the corn syrup/water mix was actually useful! User Gravityisweak brought up the idea of adding magnetic particles to the fluid and seeing what happens. Well, as fate would have it, I had a magnetic viewer filled with corn syrup/water I made a while back (added pics). You see, the magnetic particles are just tiny pieces of steel wool I cut up with scissors. The thick fluid suspends them for a long time. The added mica traces little paths as the steel wool bits move about. In retrospect, I would use less mica and wool for better visibility. Here is a link to the mag viewer 'ible (remember, corn syrup and water is what I used in lieu of oil):https://www.instructables.com/id/3D-Magnetic-Field-Viewer/

***Note: A lot of people have suggested using glycerin or Elmer's gel glue to thicken the fluid, but I haven't tested it yet. If you test it, please give us the results in the comments below!  

Step 4: Easy Viewer

For a simple and decent looking container, I used a 1 liter 'smart water' bottle. It's a near perfect cylinder which makes for easy viewing. besides being cheap, it's resilient and makes it good for kids to use. My daughter loves it. I recommend gluing the cap in place. I removed the label, which left a sticky residue. To remove it, my wife rubbed coconut oil and baking soda over it and left it for 5 minutes. After waiting, it wiped perfectly clean with soap and warm water.


Step 5: Final Thoughts

So what can you do with it?

*You can use it in a science fair project to show convection currents or aerodynamics with this lost technique.
*Make a toy for the kids or desk at the office.
*Incorporate it in a prop for a costume or movie.
*Make a killer coffee table like this guy below:

* Update: below is a simple table that most anyone can build in a day or two! Check it out:


I have some other ideas too that I am working on. If you enjoyed this instructable, stay in touch for more. I'd love to hear ideas, suggestions, and answer questions! Have fun!

8 People Made This Project!

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176 Discussions

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aperkins01096

3 years ago on Step 5

Great instructable! I'd used "PearlEx" (available at amazon.com: http://amzn.to/1ee2sP5) and it worked quite well - a little went a long way. Also added blue food coloring. Looks great with an LED lighting it from below. Thinking about making a small steel sphere inside of a very smooth sculpey losenge to put in the bottom, then setting it atop a small motor with a magnet to swirl it automatically, but haven't gotten to that one yet. Too many projects, too little time.

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gravityisweak

4 years ago

Thanks for the nice background and details of your research. I wonder how this would look when pumped through clear tubing. Do you think metallic particles could be mixed in for fancy magnet play? What would happen if you mixed the mica with both cornstarch and water for a non newtonian fluid?

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Omni DIYgravityisweak

Reply 4 years ago on Introduction

Hey, get out of my head haha! I just put some mica in a old magnetic viewer I made.

Another member asked about using oil (which didn't work sadly) to make a thicker fluid. I opted to use corn syrup mixed with water which I used for my magnetic viewer in the past. Instead of making a new batch, I just sprinkled mica into my mag viewer.

To make the magnetic field viewer, take steel wool, cut as small of shavings as humanly possible with scissors, add to water, mix in corn syrup til desired consistency. Next time I won't use as much steel wool or mica for more transparency. I'll have to put this in my additives section...

As for the tubing, I had some 8mm clear vinyl tubing I ran it through. The flow became pretty laminar/boring and it was really transparent. Still, I think with bigger diameter tubing and more mica, it would look cool. Sorry no pics; battery died :(

The non-Newtonian fluid sounds interesting, but I haven't tested that yet. Thanks for the cool ideas :)

Mag viewer.png

No, actually, the two most common forms of iron oxides (rust) are both ferromagnetic, Fe2O3 and Fe3O4 (actually ferrimagnetic, a subclass of ferromagnetism. Fe3O4 occurs naturally as the mineral known as Magnetite (for its obvious properties). Both are used in magnetic recording media and magnetic inks (The black print on US bills is printed in magnetic ink -- you can just barely pull a bill with a strong magnet).

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Omni DIYburnerjack01

Reply 4 years ago on Introduction

Not sure... I've had mine for months now and it seems to be functioning as good as the day I made it.

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The GreatA1

11 days ago

This thing is very cool applied to a rheoscopic fluid!

You can find it on Amazon or maybe somewhere else too, I don't know.

My advice is to tweak it a little to make the electrical engine to spin a little bit slower, we don't really need a tornado but something to make the fluid spinning.

The chemical stirrers are good but way too expensive and not as funny as this cute stuff! ;-)

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The GreatA1

Question 11 days ago on Introduction

This instructable is AWESOME!!! *__*

My question, tho, is the following: how can I realize a heating unit so that it can heat the rheoscopic fluid I am concocting to making it swirl and move it constantly?

I would love to do something similar like we can see in this video:

Obviously heaten up by something like an electric thermocouple or something (I'm just poking in the dark here).

Thanks for any suggestion you will give me! ^__^

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danzo321

4 years ago on Step 3

Thinking glycerin for thicker water. Other than as antifreeze, can it be bought anymore?

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The GreatA1danzo321

Reply 11 days ago

glycerin can be bought at any pharmacy (or drugstore, or chemist's shop... I don't know how is it properly called in US. The shop where you buy band aids, aspirins, thermometers, condoms and things like that ...)

At least in Italy you can do it, I know 'cause I've just bought it yesterday.

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millersharidanzo321

Reply 4 years ago on Step 3

Your rheoscopic fluid seems to work quite well, so I'm only mentioning this because I thought you might be curious. I read somewhere - can't remember where, sorry - that some rheoscopic fluid uses ground up fish scales instead of mica powder. It makes sense, but I wish I could remember where I heard it so I could check it out.

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The GreatA1

11 days ago on Step 3

I've used glycerin just yesterday but I'm learning to dose it to thicken tap water and I am quite unsure about the results so far.

For instance:

40/45g of glycerin are barely useful in ≈1000ml of tap water + 1tbs (≈15g) of mica powder. The powder remain in suspension for about 10 minutes and precipitate completely in 30.

20/25g of glycerin, on the other hand, are a little bit too much on ≈100ml glass bottle with a ≈½tbs of powder: the fluid seems way too dense and the mica seems not to flow smoothly.

I have to test a lot! Not that I feel sorry... The glycerin is not very expensive, about €3,50 per 60g and I have the empty bottles for free. I already bought a lot of mica so... ;-)

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almateus

4 years ago on Introduction

I have the pure compound they use to add to cosmetics to give the pearly effect. I can´t remember the name of the compound right now, but it is sitting on a shelf in my lab. I imagine it is much cheaper to buy the pure compound than the fluid already diluted, but only if you plan to make a lot of the fluid. It is an organic compound, insoluble in water, obviously, but it is not completely non-polar, so it it has a weak interaction with the water.

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The GreatA1almateus

Reply 15 days ago

Uhm. How the glycol stearate is used to give the pearly effect? I have read that it has to be heaten up to 65° so my educated guess is that this organic compound will cool down to room temperature and return to a solid state. Am I missing something?

I am searching for a fluid more dense than water to be used in my kalliroscopes. Or something to be added to distilled/deionized water to make it more dense so that the mica particles can float for a longer time.

I've read about clear corn syrup but I'm searching for something not organic, after all I'm not going to make it edible! :-D And tetrachloroethylene do not dilute in water, as far as I remember.

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almateusThe GreatA1

Reply 15 days ago

You just mix it with water, no need to heat it. It is an insoluble compound, but with a low density and a very fine powder, so it remains in suspension for a long time. Another thing that is important is the way it interacts with water and with its own particles. You can try to make the water more dense by dissolving a lot of salt in it. This article may be useful: https://aip.scitation.org/doi/pdf/10.1063/1.5045053. It shows how to make the fluid from shaving cream.

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The GreatA1almateus

Reply 14 days ago

I got it now. "very fine powder" are the keys! I have search for "glycol stearate" and mostly I have found out it as scales so I was a little bit puzzled but if it is delivered in powder then it makes way more sense! Thank you! ^__^

I have seen the article about extracting a rheoscopic fluid from shaving cream and I find very impressive when they recomend "shaving cream whose ingredients are water, stearic acid, triethanolamine, laureth-23, sodium lauryl sulfate, and fragrance."

You can use that and it will produce the same movement, however I haven't tried any colored mica so I don't know how transparent/light reactive it will be. Let us know if you give it a shot.

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The GreatA1Omni DIY

Reply 15 days ago

You can totally use the pre-colored mica powder. The transparency is given by how much poweder you use: the more powder you use, the less transparent (and the more reflective) the fluid will be.

The less poweder you use, the more transparent (and the less reflective) the fluid will be.

This mean, in other words, transparency reduce the "pearly" factor of the rheoscopic fluid.

In the picture I've uploaded you can see 4 examples I've made of pre colored mica powders: 500ml of water + ½tsp of powder

They look pretty nice! :-) Even in such ugly bottles!

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