US-based researchers created a stingray robot. What makes it unique is it has living cells.

This robot has an ability to swim because the researchers added muscle cells that got from rat hearts. The new study that the US-based researchers found could lead scientists to build entire living artificial hearts, which came from the muscle cells that would like a natural heart.

In an article published in the journal Science, the group said their project "may represent a path toward soft-robotic 'embodied cognition'."

Stingrays and some related fishes have flat bodies with long wing-like fins, which are used to surge in waves. The group of researchers sought to build a robot that can imitate the stingray's efficiency and maneuverability. 

Senior author and  bioengineer at Harvard University, Kit Parker, examined the stingrays. According to the scientist, the beating of their wings resembles the beating of hearts, which inspired him to use rat heart-muscle cells, 

The group started with building skeletons (which made from gold) of the robot, which they imitated from the shape of the stingrays, according to Live Science. Then, the covered the skeletons using a thin layer of stretchy plastic and a thicker body of silicone rubber.

On the top of the robot, they placed muscle cells from rat hearts, and they ensure that the robot is not heavy so it will not weigh down into a second layer.  The result of their work, the robot emulates some features of a stingray, and it can respond to light signals.

Parker said the stingray robot they created does not  have its own brain, however, it is controlled by light signals from outside. Parker also that the long-term aim of their group is to integrate neural cells and electronics into the robot, so the robot can make internal decision-making, and there is a possibility to have its own intelligence, the Financial Times reported.