Scott Waitukaitis

But doing a collision or a touch between two oxide particles is difficult.

They're so hard physically that when you do a single touch together of two samples, the contact area is minuscule.

And that means in a single, say, collision between two sand particles in the desert,

Little charges exchange, so it really takes a lot of collisions to build charge up.

Yeah, exactly.

And they charge up a lot, but they charge up a little at a time for each collision.

So that's hard because you need a really good resolution to your measurement to see how much is exchanged when they touch.

The second thing that's hard is if you hold whatever you're working with

with anything like a pair of tweezers or a rubber glove or you name it, you're going to transfer a lot of unwanted charge to the object by touching it to hold it.

Exactly.

And so what we're doing in our lab is we're using lots of different techniques in levitation where we levitate the object, and that way we can make it touch something without physically touching it to do so.

Right.

In our experiment, you know, we levitate a sphere of oxide above a plate.

Oh, yeah, sorry.

In this case, we use acoustic levitation.

So acoustic levitation, yeah, yeah, yeah.

You can levitate stuff with sound.

It's really awesome.

But basically, if you have, you know, sound is pressure waves, right?

Pressure exerts forces.