Electrowetting

Electrowetting is when you use electricity to make a tiny droplet of liquid move on a surface. It's like when you put a little bit of water on a table and then move it around with your finger, except with electrowetting, we use electricity instead of our fingers.

Imagine you have a tiny droplet of water on a special surface that's been coated with a special material. This material is called a hydrophobic coating, which means it repels water. Normally, the droplet of water would just sit there on the surface because it's not sticky enough to make it move. But when we add electricity to the hydrophobic coating material, it changes the way the droplet interacts with the surface.

The electricity basically changes the shape of the surface, like pulling a blanket tight, which makes the droplet of water spread out more. This spreading out of the droplet actually reduces the surface area that comes into contact with the hydrophobic coating material. Since the droplet is now less in contact with the surface, it becomes less attracted to the surface, which causes it to move.

By controlling the amount of electricity that's applied to the surface, we can control how much the droplet moves. And by using special electrodes, we can move the droplet in any direction we want.

Electrowetting has some amazing uses, like in digital displays. Instead of having a bunch of tiny pixels, a single droplet of liquid can be moved around to create different color patterns. It also has applications in lab-on-a-chip devices where tiny droplets of liquid need to be moved around for chemical reactions or biotechnology applications.