A Lightweight, High-Efficiency "Fluidic Engine" Could Drive Future Assistive Devices, Soft Wearables
Designed to operate free from bulky external compressors, this wearable engine delivers efficient motion in wearable artificial muscles.
Researchers from North Carolina State University's Lab of Biomechatronics and Intelligent Robots, Sandia National Laboratories, and the University of California at Berkeley have developed a "fluidic engine" that, they hope, could act as a portable driving force for a range of assistive devices.
"Soft robots that are powered by fluid engines — such as hydraulic or pneumatic action — can be used to mimic the behavior of muscle in ways that rigid robots cannot," explains corresponding author Hao Su, associate professor of mechanical and aerospace engineering at NCSU, of the potential impact for the team's work. "This makes these robots particularly attractive for use in assistive devices that improve people’s ability to move their upper or lower limbs."
The problem with fluid engines is that they're typically bulky affairs, reliant on a large-scale external power source like an air compressor to deliver a usable amount of force. The team's take on the problem, though, is untethered — yet can pump oil into and out of a soft robot's actuation camber to turn it into an artificial muscle, using nothing more than a battery-powered high-torque motor.
"We found that we were able to generate an unprecedented amount of force for an untethered engine, while still keeping the weight of the fluidic engine low," says first author Antonio Di Lallo of the team's breakthrough. "And the maximum efficiency of our fluidic engine is higher than previous portable, untethered engines."
In testing, the device — weighing an easily-portable 1.6kg (around 3.5lbs) — delivered pressures of up to 0.75MPa to drive the soft robotic McKibben muscle system to a force of up to 580 Newtons, easily outperforming rival designs in terms of efficiency. For real-world experiments, the team developed to proof-of-concept wearables targeting upper and lower limbs and designed to reduce the strain on the wearer's muscles during tasks including lifting heavy objects and ankle rotation.
The team's work has been published in the journal Advanced Intelligent Systems under open-access terms; readers with their own ideas for how technology can boost accessibility and inclusion are invited to submit them to our Build2gether 2.0 Inclusive Innovation Challenge — open now through to 15 August and with over $100,000 in prizes available.