Powered Exoskeleton - History

History

The earliest exoskeleton-like device was a set of walking, jumping and running assisted apparatus developed in 1890 by a Russian named Nicholas Yagin. As a unit, the apparatus used compressed gas bags to store energy that would assist with movements, although it was passive in operation and required human power. In 1917, US inventor Leslie C. Kelley developed what he called a pedomotor, which operated on steam power with artificial ligaments acting in parallel to the wearers movements. With the pedomotor, energy could be generated apart from the user.

The first true exoskeleton in the sense of being a mobile machine integrated with human movements was co-developed by General Electric and the United States military in the 1960s. The suit was named Hardiman, and made lifting 250 pounds (110 kg) feel like lifting 10 pounds (4.5 kg). Powered by hydraulics and electricity, the suit allowed the wearer to amplify their strength by a factor of 25, so that lifting 25 pounds was as easy as lifting one pound without the suit. A feature dubbed force feedback enabled the wearer to feel the forces and objects being manipulated.

While the general idea sounded promising, the actual Hardiman had major limitations. It was impractical due to its 1,500-pound (680 kg) weight. Another issue was the fact it is a slave-master system, where the operator is in a master suit which is in turn inside the slave suit which responds to the master and takes care of the work load. This multiple physical layer type of operation may work fine, but takes longer than a single physical layer. When the goal is physical enhancement, response time matters. Its slow walking speed of 2.5 ft/s further limited practical uses. The project was not successful. Any attempt to use the full exoskeleton resulted in a violent uncontrolled motion, and as a result it was never tested with a human inside. Further research concentrated on one arm. Although it could lift its specified load of 750 pounds (340 kg), it weighed three quarters of a ton, just over twice the liftable load. Without getting all the components to work together the practical uses for the Hardiman project were limited.

Los Alamos Laboratories worked on an exoskeleton project in the 1960s called Project Pitman. In 1986, an exoskeleton prototype called the LIFESUIT was created by Monty Reed, a US Army Ranger who had broken his back in a parachute accident. While recovering in the hospital, he read Robert Heinlein's Starship Troopers and from Heinlein's description of Mobile Infantry Power Suits, he designed the LIFESUIT, and wrote letters to the military about his plans for the LIFESUIT. In 2001 LIFESUIT One (LSI) was built. In 2003 LS6 was able to record and play back a human gait. In 2005 LS12 was worn in a foot race known as the Saint Patrick's' Day Dash in Seattle, Washington. Monty Reed and LIFESUIT XII set the Land Speed Distance Record for walking in robot suits. LS12 completed the 3-mile race in 90 minutes. The current LIFESUIT prototype 14 can walk one mile on a full charge and lift 92 kg (200 lb) for the wearer.

In January 2007, Newsweek magazine reported that the Pentagon had granted development funds to The University of Texas at Dallas' nanotechnologist Ray Baughman to develop military-grade artificial myomer fibers. These electrically-contractive fibers are intended to increase the strength-to-weight ratio of movement systems in military powered armor.