On Thursday, May 27, 2021, Queen’s University announced the development and evaluation of their backpack-mounted exoskeleton prototype was published in Science, one of the world’s foremost academic journals.
A multidisciplinary team from the Queen’s Faculty of Engineering and Applied Science created the prototype which will enable users to walk further while using less energy, according to a release from the university. The backpack-mounted prototype removes energy during a specific phase of the gait cycle, lessening the metabolic cost of walking.
“For the first time, we have demonstrated that removing energy can increase walking efficiency,” said Michael Shepertycky, recent Queen’s University PhD graduate and lead author of the study. “This is a significant advancement in the field of exoskeleton development, and one with the potential to change the way that we approach gait assistance.”
Unlike existing exoskeleton technologies that either add energy or transfer it from one phase of the gait cycle to another, the university said this new device assists users by removing energy which helps the knee muscles during a critical moment—called the terminal swing phase. The team envisages the technology—which weighs just over half a kilogram—enabling hikers to walk longer distances or helping nurses be less tired after a long shift on their feet.
“Improving walking and running economy has been an important topic of research for the past two decades, due to its scientific and practical implications,” said Dr. Qingguo Li, co-senior author of the study and Associate Professor of Mechanical and Materials Engineering, Queen’s University. “Walking is a delicate and highly optimized process, which makes it difficult to use exoskeletons to improve walking efficiency.”
In addition to assisting the user, the device converts the removed energy into electricity that can be used to power the device’s control system and other portable devices, the university said. This energy harvesting capability could be particularly useful for individuals travelling on foot in remote locations, allowing them to charge cellular phones or GPS devices. Yan-Fei Liu, Professor of Electrical and Computer Engineering and co-author of the study, led the development of the device’s power electronics.
The team’s interdisciplinary approach included elements of walking biomechanics, physiology, human-machine interactions, and design innovation. Much of this research was conducted in the Human Mobility Research Centre, a Queen’s/Kingston Health Sciences Centre facility equipped with world-class gait analysis technology.