Answer: Sound waves.
Designed to function as an on-the-go washing machine, the Sonic Soak uses ultrasound waves to remove dirt, oil and bacteria from items in the water. It creates 50,000 ultrasonic vibrations per second, which forms tiny bubbles with high pressure that clears away contaminants when they collide.
A 10.5 cm x 3.5 cm stainless-steel cylinder is responsible for creating the ultrasound waves. It is connected to a unit smaller than a smartphone that plugs into a standard wall outlet, from which the user can set the device on a timer. According to its creators, the Sonic Soak uses 10 percent less energy and 2 percent less water per cycle than your average washing machine.