Last year, scientists created the first living machines by joining cells from African clawed frogs with tiny robots. One of them used sculpted cardiac cells to propel themselves along, push payloads, and even work collectively within a swarm of other "Xenobots." And today, the same research team announced the creation of life forms capable of self-assembly into a body from a single cell, according to a new study published in the journal Science Robotics. The Xenobots can also move more quickly, navigate varying environments, and live longer than the first models -- all while working in groups and healing if and when they're damaged. Compared to the earlier model of Xenobots (or, number 1.0) -- where the millimeter-sized automatons were made in a "top-down" style via the manual placement of tissue, shaping frog skin surgically and including cardiac cells to create motion.

Scientists have designed a robotic stingray that could help our understanding of the human heart. The miniature robot, one-tenth the scale of the actual fish, moves using heart cells taken from a rat. Researchers hope the robotic ray will give new insight into the heart's ability to pump blood and its potential implications in heart disease. The research is published in the journal, Science. "It turns out the musculature in the stingray has to do the same thing as the heart does: it has to move fluids," said lead researcher, Prof Kevin Kit Parker of Harvard University, US.