A teenager from Moscow invented a toothbrush for astronauts, which can be used without water.
The toothbrush’s handle has three buttons. When you press the first button, toothpaste appears from the tiny holes between the brushes. The second button turns on a micro compressor that drives air through the brushes so that toothpaste does not stick in the holes. When you press the third button, the compressor draws the used toothpaste back into the micro container.
The invention is currently undergoing patent expertise.
