Video: Why is it impossible to hold something under water?

Perhaps this is something you have tried before: to hold something under water in an ultrasonic bath. Give it a try to hold a wafer, contact lens or cleaning indicator using a pair of tweezers in an ultrasonic bath. You probably won’t succeed!

Why not? Check out the movie below.

Explanation: between the levers of the tweezer, bubbles are being formed by the ultrasound. These bubbles push away the two levers of the forceps, which makes it impossible to hold anything between them – no matter how hard you push!