Researchers from Stanford University, Ghent University and Nike have developed an exoskeleton that facilitates travel. There is talk of a strong reduction in energy consumption and an increase in speed of up to 10%
The ankle exoskeleton could become the “means of transportation” of the future, according to a group of researchers from Stanford University, Ghent University and Nike. The thought runs to the cybernetics experiments of the most famous science fiction films, but in this case we are talking about “small” motorized devices, to be worn, capable of drastically reducing the energy cost of the race and therefore making it not only less tiring but also more performance. To be precise today, the experimental phase involves the use of emulators, since in the laboratory the support and analysis equipment are bulky.
Steve Collins, associate professor of mechanical engineering at Stanford and co-author of the research published on Science Robotics, is convinced that experiments of this type are important to better understand the efficiency of the human body in the movement phase. For example, initially, it was assumed that since the legs behave like a spring, assistance of this type was more effective; instead it is the motorized one that has proven successful.
Yes, because just wearing an off exoskeleton increases the energy cost of running by 13%. “However, experiments have indicated that, if properly powered by an engine, the exoskeleton has reduced the energy cost of running, making it 15% simpler than that without an exoskeleton and 25% easier than that with the extinguished exoskeleton, “explained the researchers. The spring version, on the other hand, increases the demand for energy, which increases by 11% compared to a condition without an exoskeleton and decreases only by 2% when the device is off.
How the exoskeleton works
The prototypes of the ankle exoskeleton are tied at the height of the shins and remotely recall the braces used in orthopedics. In practice there is an attachment to the shoe with a rope that slides under the heel and a carbon fiber bar inserted in the sole, near the toe. The electric motors, located in the laboratory a few meters from the treadmills, provide active assistance.
“Imagine someone running behind you and holding small cables attached to your ankles. Every time you detach yourself from the ground instead of doing all the work he lifts your foot for you,” said Delaney Miller, a researcher for the group. “It looks very elastic and bouncy compared to normal running. Speaking from experience, it’s really nice. When the device provides such assistance, you have the feeling that you can run forever.” In fact, enhanced assistance relieves the calf muscles of a great load of energy.
Positive confirmations also from eleven expert runners who took turns on the treadmill. They had to get used to the exoskeleton emulator before the test and at the same time there was a need to customize the operation to adapt it to the cycle and gait phases.
10% speed increase
In any case, in the tests, by detecting the energy production using masks that measure inspired oxygen and exhaled carbon dioxide, an improvement in efficiency was confirmed which could allow an increase in running speed of up to 10%. “This threshold could be even higher if runners had additional time for training and optimization,” the researchers assured.
The increase in efficiency achieved, according to the Stanford University team, would justify the development of exoskeletons of this type for use in everyday life. On the other hand, it is their opinion that it is possible to create versions with reduced dimensions, and considering that the entire research has been financed by the National Science Foundation and Nike, it is to be believed that it is not just a wish.
“You can almost think of it as a form of transportation,” stressed the researcher Guan Rong Tan. “You could get off a bus, put on the exoskeleton and cover the last 1-2 miles (1.6 to 3.2 km, Ed) to go to work in five minutes without sweating.”
Professor Collins admitted that he has never seen a device applied to running so efficiently. “So, you probably won’t be able to use it to qualify for a race, but it may allow you to keep up with your friends who run a little faster than you. For example, my younger brother ran the Boston Marathon and I’d like to be able to keep up, “Collins said.