Researchers at Northwestern University have created a dime-sized robot that looks like an animal you might find at the bottom of the sea. The soft robot is almost 90 percent water by weight. It has a hydrogel exterior while its nickel skeleton allows it to change shape.
It doesn’t use hydraulics or electricity to move around. Instead, the researchers used a chemical synthesis process to program molecules to respond to light. When the robot is exposed to light, the molecules can repel water. Its legs can then stiffen, shifting it from a flat position to a standing one.