A chemical claw machine bends and stretches when exposed to vapors

Scientists have developed a tiny ‘claw machine’ that is able to pick up and drop a marble-sized ball in response to exposure to chemical vapors. The findings point to a technique that can enable soft actuators–the parts of a machine that make it move–to perform multiple tasks without the need for additional costly materials. While existing soft actuators can be ‘one-trick ponies’ restricted to one type of movement, this novel composite film contorts itself in different ways depending on the vapor that it is exposed to.