Magnetic spray transforms inanimate objects into mini-robots

Scientists have engineered a spray that turns inanimate materials into mobile, insect-scale machines. The spray contains particles of iron, polyvinyl alcohol and gluten, which combine with water to form sticky, magnetic skins, or “M-skins.” Thanks to the spray’s magnetic properties, the scientists managed to bring ordinary objects to life, like origami paper and cotton thread, according to a paper published last week in Science Robotics. The researchers captured footage of the “millirobots” rolling, swimm