Walk With Less Effort And Save Energy With These Exoskeleton Boots
A team of engineers from Carnegie Mellon University, led by Steven Collins, has developed a mechanical exoskeleton boot that reduces the energy needed to walk by 7% compared to normal footwear. Details of which made news in the inventors’ report on April 1.
A significant innovation in this exoskeleton is the fact that it doesn’t use any sort of external power source rather relies on a spring-and-ratchet mechanism that maps on human physiology.
The claimed 7% energy reduction takes place in the walker’s calf muscle, as that energy gets stored as elastic energy in a spring running parallel with the Achilles tendon. This 7% reduction is almost equivalent to taking off a 10-lb (4.5 kg) backpack and thus equals the amount of energy saved by the exoskeleton boot.
A lot of research effort was put in the making of passive-force exoskeleton boots. Researchers deliberated on the biomechanics of walking and examined ultrasound imaging which showed that the calf muscle along with exerting a pushing force, when a person moves forward, also perform a clutch-like action to keep the Achilles tendon taut.
So what goes behind the real working of this boot is that some of this clutching force is shared by the passive-elastic device, hence reducing the overall metabolic rate of walking. The mechanical clutch produces this force without consuming any energy.
It does this by ‘locking’ the calf muscles, keeping them from stretching – quite a prevalent inefficiency in muscle physiology, says neuro-mechanist Max Donelan, at Simon Fraser University in Burnaby, Canada. Mechanical clutches have an advantage over muscles because they lock into place without consuming energy, he says.
The advancement is going to have a major impact in all developments relating to exoskeletons because none have come close to introducing passivity. Only powered exoskeletons or running blades for amputees were similar to some extent.
Commenting on the development of the exoskeleton boots, Team-lead Steven Collins said:
It’s only been in the last couple of years that any machine reduced the energy cost of walking and the first devices to do so were powered exoskeletons. They partly replace the energy used by muscles with an external artificial source.
What we wanted to see was whether we could reduce energy costs with an unpowered device and the thing that makes that more difficult and interesting is that it’s sort of like changing the structure of the body to make it more efficient.
Those kind of structural changes could have been discovered through evolution. But what we wanted to do was leapfrog evolution in making the structure of the body more efficient.
Even though still in the prototyping phase, researchers are still very much hopeful that idea is feasible enough to manifest into a real commercial product. Cost of which may not go beyond that of normal ski boots.