Here is a robotic leg powered by HASELs. What are those exactly? They are electro-hydraulic artificial muscles known as HASEls. This leg can jump across grass, pebbles, and rocks with agility. These artificial muscles are self-sensing, so they can detect collisions with obstacles to overcome them. This robotic leg doesn’t use any energy while still.
This robotic leg is a Max Planck ETH Center for Learning Systems research project. The above video shows it in action.