Hero's engine is a famous steam engine attributed to Hero of Alexandria in the 1st Century AD. The concept is simply pressurized gas made to escape through tubes that generate torque and rotation. This is usually done with heating water but the famous Action Lab YouTube channel takes this a step further.
He first places the engine inside a vacuum chamber and boils the water through lowering pressure, which causes the engine to work even in a vacuum.
The next demonstration involves using liquid nitrogen instead of water. At room temperature the nitrogen boils thus expanding quickly. This expansion causes Hero's engine to rotate so fast that the engine breaks apart! Awesome stuff!