Soft Robots are Getting a Heart, Thanks to Electronically Powered Pumps

Researchers have come up with electronically powered deformable pumps to give hearts to soft robots.

So, what if they are not humans! what's stopping them from having a heart?  A collaboration between Cornell researchers and the U.S. Army Research Laboratory has leveraged hydrodynamic and magnetic forces to drive a rubbery, deformable pump that can provide soft robots with a circulatory system, in effect mimicking the biology of animals.

According to Rob Shepherd, associate professor of mechanical and aerospace engineering in the College of Engineering, who led the Cornell team, these distributed soft pumps operate much more like human hearts and the arteries from which the blood is delivered. He also believes that this combination of a robotic heart with the previously invented robot blood will help make a more lifelike imitation of humans.

Description of the Robotic Heart

The new elastomeric pump made by the researchers is formed with a soft silicone tube fitted with coils of wire, known as solenoids that are spaced around its exterior. Gaps between the coils allow the tube to bend and stretch. Inside the tube is a solid core magnet surrounded by magnetorheological fluid, a fluid that stiffens when exposed to a magnetic field, which keeps the core centered and creates a crucial seal. Depending on how the magnetic field is applied, the core magnet can be moved back and forth, much like a floating piston, to push fluids such as water and low-viscosity oils going forward with continuous force and without jamming.

The researchers conducted an experiment to demonstrate that the pump system can maintain a continuous performance under large deformations, and they tracked the performance parameters so future iterations can be custom-tailored for different types of robots. "We thought it was important to have scaling relationships for all the different parameters of the pump so that when we design something new, with different tube diameters and different lengths, we would know how we should tune the pump for the performance we want," Shepherd said.

The group's paper, "Magnetohydrodynamic Levitation for High-Performance Flexible Pumps," was published July 11 in Proceedings of the National Academy of Sciences. The paper's lead author was postdoctoral researcher Yoav Matia.