A collaboration between the U.S. Army Research Laboratory and Cornell University researchers has seen the development of a novel, flexible “heart” for soft robots. The pump-like device uses magnetic and hydrodynamic forces to work, acting to move energy around the robot’s body much as a human or animal heart moves blood. 

The new breakthrough was unveiled in a paper published this month in the journal PNAS.

Previous attempts to create a robot heart struggled to find the right material and minimize energy use, with electronic pumps being too bulky and stiff to operate within a robot’s body and causing cost and efficiency losses as a result. 

“These distributed soft pumps operate much more like human hearts and the arteries from which the blood is delivered,” said Rob Shepherd, Cornell team study lead. “We’ve had robot blood that we published from our group, and now we have robot hearts. The combination of the two will make more lifelike machines.”

The researchers’ novel pump type is made out of silicone and coils of wire, with a solid core magnet at the center surrounded by magnetorheological fluid – a substance that stiffens when exposed to a magnetic field. As such, users can move the core magnet back and forth by adjusting the magnetic field applied to it, using this action to pump fluids through the robot.

In testing the new pump system, the researchers demonstrated its capacity to maintain continuous performance even if the heart takes on differing shapes, meaning the pump can be tailored for different robots and unique requirements.