You’ve probably seen those experiments where scientists are able to levitate foam balls, or tiny drops of water, using nothing but ultrasonic sound waves. It’s utterly mesmerizing to watch something ...

If you play around with an ultrasound field for long enough, you can set up standing waves that allow you to levitate water drops in mid-air—but that’s only where the fun starts. The drops, held in a ...

A new water-integrated droplet electricity generator produces high electrical output while floating on water surfaces. Raindrops are not only a source of fresh water, they also carry unused energy ...