Liquid metal imbalance of the surface tension induces a pressure difference between the rear and the head, which produces a thrust to drive the droplet toward the head; at the same time, the hydrogen produced in the electrochemical reaction process also further raises the thrust. The discovery of this phenomenon laid the technical foundation for the development of intelligent motors, vascular robots, fluid pumping systems, flexible actuators and even more complex liquid metal robots. Liquid metal Liquid metal consists of alloys with very low melting points which form a eutectic that is liquid at room temperature. The standard metal used to be
Space Shuttle external tank plates together. When the orbiter GPCs command external tank separation, the bolts are severed by pyrotechnic devices. The ET has five propellant umbilical valves that interface with orbiter umbilicals: two for the liquid oxygen tank and three for the liquid hydrogen tank. One of the liquid oxygen tank umbilical valves is for liquid oxygen, the other for gaseous oxygen. The liquid hydrogen tank umbilical has two valves for liquid and one for gas. The intermediate-diameter liquid hydrogen umbilical is a recirculation umbilical used only during the liquid hydrogen chill-down sequence during prelaunch. As the ET is filled, excess gaseous hydrogen