Microparticles Self-Assemble into Spinning Gears

Self-assembly is common in nature, as living systems are biochemical machines that excel at building and moving their parts. Funded by the National Science Foundation, researchers at University of California San Diego and New York University have developed a new way to mimic self-assembly in the lab, coaxing specially-designed microscopic objects into small, gear-like machines. The building blocks are self-powered microparticles that propel after being activated by light. The researchers designed them to autonomously sense light gradients and navigate in light patterns. They call the result a "machine made of machines."