Engineer – Portable engine powers artificial muscles in assistive devices

The solution, developed by researchers from North Carolina State University, Sandia National Laboratories and UC Berkeley, is designed to generate significant force without the need for an external power source.

In a statement, Hao Su, corresponding author of a paper on the subject, said: “Soft robots powered by hydraulic or pneumatic motors can mimic the behavior of muscles in a way that rigid robots cannot.

“This makes these robots particularly attractive for use in assistive devices that improve people’s ability to move their upper and lower limbs.”

Most liquid engines are physically connected to an external power source, such as a large air compressor, which limits their usefulness. Previous liquid engines that were not connected to external power sources were not able to generate much force, which also limited their usefulness.

“Our work here solves both of those problems,” said Su, an assistant professor of mechanical and aerospace engineering at NC State. “Our fluidic engine is not tethered to an external source, but it can still generate up to 580 newtons of force.”

The new motor works by pumping oil into and out of a chamber in the soft robot, NC State said, making the soft robot behave like an artificial muscle that contracts and relaxes.

The fluid motor pump is driven by a high-torque battery-powered motor, which allows it to generate significant pressure, allowing the artificial muscle to exert significant force.

In concept tests, scientists evaluated the force the new engine could generate, as well as its efficiency in converting electrical energy into jet energy.

“We found that we could generate unprecedented force for a tetherless motor while keeping the weight of the fluidic motor low,” said Antonio Di Lallo, the paper’s first author and a postdoctoral researcher at NC State. “And the maximum efficiency of our fluidic motor is higher than that of previous portable tetherless motors.”

Paper, “Independent Fluid Engine for High-Force Soft Wearables “Robots” was published in Advanced intelligent systems.

This work was supported by the U.S. National Science Foundation, the National Institute on Disability, Independent Living, and Rehabilitation Research, and Amazon Robotics.