Cool science: Watch water droplets navigate a maze

From the American Chemical Society.

WASHINGTON — Have you ever seen a drop of water navigate a maze? It’s possible thanks to the same phenomenon that lets you know if a griddle is hot enough for pancake batter. Water droplets that dance and skitter across a hot surface instead of boil away on the spot are experiencing the Leidenfrost effect.

Understanding Leidenfrost — first described more than 200 years ago — helped engineers make more efficient steam engines. Today, scientists are using high-speed cameras to better characterize how superhot water behaves on metal surfaces. The investigation might lead to improvements in power generation. Watch the superhot dancing droplets here:

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M Courtney
May 17, 2017 12:46 pm

Cool.
Ironically.

MarkW
Reply to  M Courtney
May 17, 2017 12:57 pm

Looks more like stainless steel.

commieBob
May 17, 2017 12:51 pm

Leidenfrost! My inner twelve year old is amused.

J Mac
May 17, 2017 1:02 pm

Hot Spit!

J Mac
May 17, 2017 1:04 pm

Love the selective machining/texturing of the metal surfaces, to change the force vector of the resulting steam!

May 17, 2017 1:34 pm

Nobel winner Hans Alfven wrote a book , https://www.amazon.com/Worlds-Antiworlds-Antimatter-Cosmology-Hannes-Alfv%C3%A9n/dp/0716703173 , postulating that every other galaxy might be anti-matter separated from those with our handed matter by the equivalent of a Leidenfrost phenomenon keeping them apart .

May 17, 2017 1:34 pm

Liquid Nitrogen is (like) boiling water at -273F (iirc)

Bruce Cobb
May 17, 2017 1:51 pm

Wunderbar!

May 17, 2017 1:53 pm

Nice one, brightens up the morning.
Here is a link to another recent experiment with outstanding yet disturbing results.
http://www.organicandhealthy.org/2017/05/high-school-science-experiment-leads-to.html

Robert of Texas
Reply to  ozonebust
May 17, 2017 2:26 pm

No attempt to measure additional heat or evaporation caused by being near (or on) an electrical device – if its on then it produces heat.
Just like most other effects, one must consider all possible variables, not just the one the tester advocates.

J Mac
Reply to  ozonebust
May 17, 2017 2:27 pm

Very interesting! Thanks!

Auto
Reply to  J Mac
May 17, 2017 3:15 pm

Another effect that can be employed . . . . . .
I gather it already is!
Wonderful.
Auto

Thomas
Reply to  ozonebust
May 17, 2017 3:18 pm

I’m 99% sure that’s fake news. Real scientists have been unable to find any negative impact on humans from radio frequency electro-magnetic radiation.

Reply to  Thomas
May 17, 2017 5:33 pm

Then I suggest that you try the experiment yourself, that way you can be 100% confidnt in either direction

Reply to  ozonebust
May 17, 2017 3:42 pm

Even the idiot site snopes disputes the results. Very doubtful of the results.

jorgekafkazar
Reply to  ozonebust
May 18, 2017 10:45 am

Probably not a very well-controlled experiment.

Paul Penrose
May 17, 2017 1:57 pm

I didn’t know there was a name for this phenomenon. Thank you for posting this!

Kasuha
May 17, 2017 1:57 pm

That original video is 3 years old now.

Ron Williams
May 17, 2017 2:24 pm

Yes, I never knew the term Leidenfrost before now, but I knew instinctively why the water on a much hotter surface reacted the way it does. Very interesting how they discovered that they could harness the effect by machining the metal in acquiring the rotational energy. Will be interesting to see if this has any widespread application.

Bryan A
Reply to  Ron Williams
May 17, 2017 2:29 pm

Could be used to move water up hill

Editor
Reply to  Bryan A
May 17, 2017 3:23 pm

Incredibly inefficiently. The energy to do it is coming from boiling water. However, if you have a bunch of heat and nothing better to use it for, go right ahead!

Jeffrey Mitchell
Reply to  Bryan A
May 17, 2017 11:59 pm

Also used in steel rolling mills. As the hot steel is being flattened, they pour water on it to cover the steel with steam which then prevents oxidation. When I was a student over 30 years ago in an environmental class, we visited the Geneva Steel plant in Utah and got to watch this phenomenon.

Butch
May 17, 2017 2:47 pm

Anthony , just so you know, your next post, ” Our Canadian Friends”, is not found ?

Sara
May 17, 2017 2:57 pm

I love the Leidenfrost effect! I may get a t-shirt printed with ‘Leidenfrost was right!’ on it. That will confuse people.
Now, if only these people who bring us science programs can explain selective hearing in cats, I will be happy.

Ron Williams
Reply to  Sara
May 17, 2017 4:06 pm

I think it would be a great name for a German Beer! Now I am craving a frosty mug…

Reply to  Sara
May 17, 2017 9:57 pm

Evolution, my dear, evolution… The first to get to the location of the can opener is obviously the fittest.

May 17, 2017 3:01 pm

Superheated steam is extremely acidic, it attacks metal turbine blades, causing pitting, which causes a drop in efficiency.
Read once where steam driven turbines only operate at about 50 percent efficiency because of the above. Good research, well worth it.

Thomas Graney
May 17, 2017 4:48 pm

People who design heat exchangers are familiar with the concept of film boiling. If the temperature between the two fluid is too high, a vapor film ensues which causes heat transfer to suffer greatly.

gnomish
May 17, 2017 5:47 pm

that was awful – yeah, the science was in there but it was pitched to a 6 yr old and the ripped off content was not credited. like this bit:

Jay Dunnell
May 17, 2017 6:14 pm

Aw, now that is the culinary secret to AWESOME pancakes. Using it this weekend!

RobertR
May 17, 2017 6:52 pm

I remember about 50 years ago Scientific American had a wonderful column, The Armature Scientist. One column was on this effect – an experiment, a hot skillet and a water drop. What was the temperature where a water drop had the longest life? If I recall 50 to 70 seconds was possible. Too hot or too cold would shorten the life of the drop. Of course pressure is also a factor. In nuclear reactors a critical parameter is DNBR, departure from nucleate boiling – the place where film boiling begins and heat transfer drops dramatically, i.e. where the drop of water floats on the steam.

Yirgach
May 17, 2017 7:13 pm

And because of the Leidenfrost effect, you can grab things like frozen nitrogen ( for a bit) without damage…

Yirgach
Reply to  Yirgach
May 17, 2017 7:17 pm

It’s the delta in temp which makes it work…

Stu
Reply to  Yirgach
May 19, 2017 12:28 pm

No. The delta T has to include liquid/gas phase change,

Yirgach
Reply to  Yirgach
May 20, 2017 5:47 pm

@ Stu May 19, 2017 at 12:28 pm
So the delta from -321F to +96.8F does NOT include a liquid /gas phase change?

May 17, 2017 10:52 pm

As I recall, it was the Leidenfrost effect that led to the melt-down at TMI-2. The operators turned off the safety injection system, allowing the fuel rods to heat up to above the Leidenfrost temperature. Eventually the operators turned the safety injection system back on but the surface of the fuel rods was too hot to be cooled by the water.

Mark - Helsinki
May 17, 2017 11:42 pm

It navigates as much as water “navigates” through a crevice.
Path of least resistance.

Sid F
May 18, 2017 1:52 am

When I played the video, part way through I go a scam pop up saying I needed a critical firefox update. Did anyone else get that?

Sid F
May 18, 2017 1:54 am

I should have said I got the scam pop up from the first video in the post.

Bruce Cobb
May 18, 2017 5:06 am

Then there’s the lederhosen effect. Usually only seen during Oktoberfest though.

Bob boder
Reply to  Bruce Cobb
May 19, 2017 10:54 am

You can see during Oktoberfest! a mighty man you must be, i myself see only drifting smudges.

Solomon Green
May 18, 2017 11:50 am

Thanks. Fascinating. I passe d it on to the cook and our offspring.

Stu
May 19, 2017 12:27 pm

I did a science fair project on this in 1978. Went to the International Science and Engineering Fair with it.

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