The STAR, short for Smart Tissue Autonomous Robot, operated on the soft tissue of pigs to reconnect two ends of an intestine, which is said to be one of the most intricate and delicate tasks in abdominal surgery. 

"The STAR performed the procedure in four animals and it produced significantly better results than humans performing the same procedure," said senior author Axel Krieger, an assistant professor of mechanical engineering at Johns Hopkins' Whiting School of Engineering.

The STAR has high repetitive motion and precision capability. Along with high precision imaging for accuracy, researchers say it can adjust to soft-tissue changes in real-time. Soft-tissue can be tricky to operate on — for humans or a robot — because the subtle movements in the texture are unpredictable.