Scientists have developed a tissue-based soft robot that mimics the biomechanics of a stingray, which could lead to advances in bio-inspired robotics, regenerative medicine and medical diagnostics. The simple body design of stingrays, specifically, a flattened body shape and side fins that start at the head and end at the base of their tail, makes them ideal to model bio-electromechanical systems on. The 10-millimetre long robot is made up of four layers: tissue composed of live heart cells, two distinct types of specialised biomaterials for structural support, and flexible electrodes. Imitating nature, the robotic stingray is even able to "flap" its fins when the electrodes contract the heart cells on the biomaterial scaffold, according to the study published in the journal Advanced Materials. "The development of such bioinspired systems could enable future robotics that contain both biological tissues and electronic systems," said Ali Khademhosseini, from University of California, Los Angeles in the US. "This advancement could be used for medical therapies such as personalised tissue patches to strengthen cardiac muscle tissue for heart attack patients," Khademhosseini said.