Hello, the internet. I'm Gav.
Welcome to this Slow Mo Guy.
A lot of the videos I try and make
are around familiar subjects.
Something you may seen a few times
or even used but then you get to see it in slow mo.
This video is nothing like that.
It's about a very specific piece of lab equipment
called an ultrasonic homogenizer or a sonicator
as it's sometimes known.
There's a bunch of applications for this
but one of the main ones
is you can use it to mix liquids
that wouldn't usually mix.
Like oil and water, for example.
And how it does it is by vibrating this tip,
this little metal tip tens of thousands of times per second.
This one will vibrate up and down just slightly
about 30,000 times in a single second.
And we're gonna see what that looks like in slow mo.
Obviously, because it's 30,000 times a second,
if I use the regular Phantom Flex4K,
we're limited to 1,000 frames a second in 4K,
which means it'll be moving 30 times up and down
in a single frame.
That's no good.
We do need to go faster.
We ideally need to be at frame rates higher
than 30,000 frames a second.
And a lot of the time,
in an actual science lab,
you'll see these in their own little enclosures
with a door but this isn't as fancy.
This is the cheapest one I could find
and it didn't come with any of that.
So we're just gonna stick it in this little clamp
that I may or may not have stolen from the set
of Planet Slow Mo.
As you know, on this channel,
for 90% of the videos,
we use the Phantom Flex4K,
which is a very lovely 4K image
at 1,000 frames a second.
But when we need to go faster than that,
we typically use one of the V series camera.
It's the 2511 supplied by Destine,
which is a science camera.
Much lower resolution but much faster frame rate.
Okay, let's start with just a simple glass of water
just to see its effects on the liquid.
Got our macro lens on
so we'll get really close to the tip.
I'm gonna start full resolution,
which will give us 28,500 frames a second.
Oof, so loud.
Wow, this is interesting.
Yes, so what we're seeing here is cavitation bubbles.
Basically the sonicator is moving so fast
and so frequently that it's just tearing
these little voids in the water where a bubble forms
but there's not actually air in there.
It's just a gap in the water.
And then the forces opposing that cause it
to collapse in
but because the sonicator is moving so fast,
they're constantly opening and closing
to create these shock waves all throughout the ripple
and every time one of these bubbles implodes,
it also creates heat.
And it seems to be causing the liquid
to flow straight down from the middle
and then around the sides.
So I think if we do this again with oil on the top,
we'll see the oil get sent down the probe.
So here I'm adding some vegetable oil.
Quite a large serving.
But this should mix them together
into a sort of emulsion.
Ah yes, so you can see the flow it creates.
All of the bashed liquid goes straight down the middle
of the tip.
So all the oil is then drawn in to fill that void.
So it actually gets mixed down the probe
and then spreads out to the sides.
You can see here that the oil
is sending the tip out of focus
but you can see here, it's smashing the oil
into tiny particles.
Okay, we've seen what it does submerged in liquid.
Now I just wanna see what it does to a single drop,
balanced on the top.
I'll film this about 40,000 frames a second.
All right, instantly vaporized.
Just smashed into about a million pieces.
It even got the stuff that I'd spilled further down
and it collected in the base of the sonicator head.
Whoa.
It looks so big.
It scales it up so much.
This is like a scaled-down version
of what the scarecrow was trying to do in "Batman Begins"
where he's trying to use the ultrasonic weapon
to vaporize all the city's water.
Just absolutely aerosolizes all of it.
Just makes it completely breathable.
I can tell because of the way the camera can't decide
what color to make them,
some of these droplets are smaller than a single pixel
on the sensor.
And it looks as though as the sonicator
is moving up and down,
the downward movement is drawing the air into it
so that as the droplets are coming back around,
they're getting sucked back on
and just punched even smaller.
All right, let's just do one obscenely fast
so we can actually see the proper movement
of the sonicator head.
We won't see much in terms of detail here
because we're not even 400 pixels wide in this resolution
but we do have 171,000 frames a second
and I need so much light for this shot
that even just slightly offsetting
my back light looks completely pitch black.
So the only way I can see anything
is by shining the light directly in the lens hole.
The exposure time is so low
that the light refracting through the droplet
isn't even bright enough.
Okay, I'm talking to you know from the edit
as we analyze this clip.
I wanna find out how long it takes
for the sonicator to do a full up-down cycle.
So I'm just gonna speed it on a little bit here
so we can see it.
If we do the maths and divide one second by 30,000,
it gives us 0.00003333 of a second.
So I if pull up the absolute time here,
we should be able to look at time directly
for the answer instead of using the calculator.
Firstly, pay attention to how slowly
the second is ticking by.
Even on milliseconds,
ticking by painfully slowly at this speed.
So we're mainly looking in the microsecond area.
I'm now gonna slow the foot down
in post to about 10%,
giving us the equivalent
of almost two million seconds a frame playback.
And then we'll pick an arbitrary up and down cycle
and just pay close attention to the time.
Yeah, so that's very close.
That's a difference, that's .000035
as opposed to what we calculated there with the .000033.
So slightly slower than the 30 kilohertz
but definitely in that ball park.
Interestingly, there are some forms
of humidifiers you can buy,
which use ultrasonic tech like this
to smash water up and get it in the air.
It's one way of humidifying a room.
Doing it one drop at a time though, not recommended.
It will take you much, much longer
to increase your relative humidity.
I now want to learn whether an apple enjoys being vibrated
at a very fine point at 30 kilohertz.
Burning it, oops.
Sonicated the Phantom there a little bit.
It seems to be causing such tiny concentrated pockets
of heat that the apple is just immediately burning
at that point.
It's crazy that if my frame rate is below the frequency
of the sonicator, it just looks like a blurb.
Because it's moving back and forth so many times,
the picture of it is being taken
at a different spot each time.
So it just looks like a blurry slow thing
when it's actually a supremely fast punchy thing.
This is bizarre.
I'm not sure whether this is creating any cavitation bubbles
in the liquid of the apple
or whether it's just shear friction.
We should try this on something
that doesn't have any moisture in it.
It still seems to be able to cook its way through wood.
Whoa.
There's no way I'm not wrecking this thing.
This is just the friction.
This could potentially be used as a fire starter.
I bet you could get am ember
if it's actually causing the wood to smoke.
This thing's a fire hazard.
Will it go through the cloth of my lab coat?
Okay, three, two, one.
Oh, immediately.
Absolutely no resistance at all.
I'm gonna try an old T-shirt.
If I can find where this is.
All right, I blocked your few of that,
sorry about that.
You'll get to see it on slow mo there.
Yeah, then when one of the holes gets big enough,
the whole thing just smashes through.
Well, there we have it.
Some very interesting and rather bizarre footage
of the intended use and also some unintended use
of a ultrasonic homogenizer.
I may have wrecked it.
It is looking slightly charred at the end now.
I mean, I don't really plan on using it again.
I'll stick it in a box just in case though.
If you can think of any other lab equipment
that would be very interesting
to see how it work in slow mo,
let me know in the comments.
I might be able to get my hands on some
and do another one of these.
Hopefully you enjoyed that video.
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See you next time.