Run 50% Faster With Catapult Exoskeleton Running Shoe Device

David Braun and his team and conceptually solved how to finally enable a high technology version of spring enhanced running where we could go 70% faster than Usain Bolt. They will have a prototype version in one year which with material limitations could finally enable faster running than our best sprinters.

The prototypes should appear next year.  Hopefully, they can help a state sprinter beat top Usain Bolt class sprinter. AA State male sprinters have a 11.3 second qualifying time. This is up to 20% slower than a top Olympic sprinter.

Reasonable near term systems could see speed skating speeds. Currently, the top running speed is 12.3 meters per second or 27 miles per hour. Speed skating gets to 15 meters per second or 33 miles per hour.

The technology and materials will need constant refinement. The progress could be like the improvement in cycling technology and materials or the technology in formula one racing cars.

They will need to increase energy storage by over six times beyond carbon fiber springs to reach the best system. Getting two to three times better and reducing weight could get us to 15-18 meters per second or 33-40 miles per hour.

Technological innovations may enable next-generation running shoes to provide unprecedented mobility. Researchers found that the top speed of running may be increased more than 50% using a catapult-like exoskeleton device, which does not provide external energy. They have uncovered the hidden potential of human performance augmentation via unpowered robotic exoskeletons. This will lead to a new-generation of augmentation devices developed for sports, rescue operations, and law enforcement, where humans could benefit from increased speed of motion.

The top speed of human running, 12.3 m/s, is near half the top speed of cycling, 21.4 m/s, despite both motions being human-powered. The lower speed of running suggests that humans have untapped energy-supplying capability, which can be used in cycling but cannot be used for faster running.

Cycling is faster than running partly because
(i) the rolling motion of the wheels prevents collisional energy losses from stepping but also because
(ii) wheels can support the weight of the body in place of the legs while
(iii) pedals enable the human to supply energy continuously in the air instead of intermittently when the leg is on the ground.

These three features enable the bicycle to double the top speed of running, despite supplying no external energy and adding weight to the human. The same features may lead to novel augmentation devices that could increase the running speed using untapped human power, without wheels or external energy.

Augmented running could theoretically enable the human to provide energy 96% of the total step time (black triangles), similar to what is analytically predicted by the spring-mass model (blue line). If that was possible, the time to supply energy in augmented running could be more than the 20% in natural running and 50% in ice-skating and would be close to the continuous limit of 100% in cycling.

The top speed would be about 20.9 meters per second or about 46 miles per hour. Getting halfway from top human running to top cycling would 38 miles per hour.

The catapult action needs an energy-storing element, for example, tendon in animals or spring in robots. It is first preloaded in the air by an actuator, muscle, or motor, and then used to push against the ground faster than the actuator could alone do. While a typical catapult that uses a fixed stiffness spring may amplify both the power and the force of a limb, it could not change its stiffness as required to redirect vertical motion and accelerate horizontal motion of the human at different speeds. Augmented running requires the use of a variable stiffness catapult.

The best spring system would need to transfer all the energy supplied by the legs in the air to accelerate the forward motion of the body on the ground. If energy is supplied only 60% of the total step time, the reduced top speed of augmented running, 18 m/s.

The theoretical top speed of 20.9 m/s would need springs to store 930 J energy and weigh no more than 1.5 kg and the stiffness of the spring should reach one order of magnitude beyond the maximum stiffness of the leg in natural running.

Variable stiffness springs may be designed with a wide stiffness range and carbon fiber–reinforced polymers or air-springs have high energy capacity while being lightweight.

However, state-of-the-art fixed stiffness running springs made from carbon fiber offer only about 150 J/kg which is an order of magnitude less than what is required to reach the predicted top speed of augmented running.

Nextbigfurure Email Interview With David Braun

Q Is there any commercial or military interest?
A We expect both. (This is the first time the work is released.)

Q Will the system be deployed for testing?
AThe prototype is underway. Testing will start within a year.

QWhat is the price of the system? (Know you don’t have this right now – feel free to skip or theorize on potential pricing)

AThe price depends on the benefit the system provides, similar to bicycles (racing bikes cost significantly more than leisure bikes). Catapult shoes will cost more than a bicycle as they require a high-tech component, a programmable spring, instead of the gear transmission.

QWhat are the most promising niches for exoskeleton? (In your opinion!) Bicycles, dirt bikes and electric bikes, folding bikes can provide 50-100mph speed with the ability to take cargo. Plus there are cars etc… Powered bikes can reach those top speeds.

APeople are obsessed with new performance augmentation devices.
Catapult shoes that enable fast legged locomotion may be advantageous to wheeled systems in the urban environment.

Catapult shoes may initiate a new sport (at the Olympics) similar to ice-skates and bicycles.

Catapult shoes are not alternatives to cars that use motors to move fast without providing a benefit to the body.

Catapult shoes promote healthy lifestyle and may benefit society at large.

SOURCES- Vanderbilt University, Science Advances, Wikipedia, Email Interview David Braun
Written By Brian Wang,