Soft robots that bend and stretch are cool concepts, but there's usually a lot of clunky hardware involved to make them work, like air compressors and gas generators. They're seldom practical in real life. However, Okayama University researchers have developed a tiny pneumatic actuator that should make those squishy automatons viable. The machinery changes pressure by turning water into hydrogen and oxygen (through a catalyst) in a matter of seconds, and reversing that process about as quickly. All it needs to get going is some electricity -- it doesn't require moving parts or vents, and it's effectively silent.