Swarms of tiny robots coordinate to achieve ant-like feats of strength

New Scientist 

Swarms of tiny robots guided by magnetic fields can coordinate to act like ants, from packing together to form a floating raft to lifting objects hundreds of times their weight. About the size of a grain of sand, the microrobots could someday do jobs larger bots cannot, such as unblocking blood vessels and delivering drugs to specific locations inside the human body. Sperm caught breaking Newton's third law of motion Jeong Jae Wie at Hanyang University in South Korea and his colleagues made the tiny, cube-shaped robots using a mould and epoxy resin embedded with magnetic alloy. These small magnetic particles enable the microrobots to be "programmed" to form various configurations after being exposed to strong magnetic fields from certain angles. The bots can then be controlled by external magnetic fields to perform spins or other motions.