Exoskeletons, in the natural state, refer to the hard shell or 'skins' of insects (such as beetles and cockroaches) and crustaceans (shrimps and crabs). An exoskeleton is a hard outer structure which provides form, structure, protection, and support to the 'soft' inner workings of a creature. This is unlike that of birds and other animals (including humans) where the skeleton is "internal" – the bones and internal organs are covered by skin, fur or feathers.

The key difference is protection. The exoskeleton in insects and crabs act as armor for the internal organs. It also provides the creature with a frame or structure. In a way, the metal full body armor of knights can be called an exoskeleton as it provides a hard shell or skin to protect the knight in a battle. Space suits and the deep-diving "JIMM" suits are also exoskeletons since they help people work normally in extremely hostile conditions.

Scientists, however, are extending the idea even further. Exoskeletons now refer to "supersuits" or systems that expand or augment a person's physical abilities. They help a person lift or carry heavier loads, run faster and jump higher. In the military, exoskeletons will help a soldier fight better since he can be better protected, carry more weapons and equipment, and have more strength than a 'normal' person has.

Challenges in the Development of Exoskeletons for HumansExoskeleton for Humans

Although the idea of exoskeletons has been around for decades in sci-fi movies, it has never been a practical concept because of basic technological limitations.

Power is a major obstacle. The power source of an artificial exoskeleton has to be portable and it has to provide sufficient energy for the tasks assigned to the wearer of the exoskeleton. The power source should also not run down in the middle of an action.

Movement is another problem. A human being can walk, run, and bend forward and backwards as well as from side to side. All these are complex movements that have proven difficult to mechanically emulate.

Human Exoskeleton Trials

In 2001, the US Defense Advanced Research Projects Agency (DARPA) decided to overcome the technological issues to exoskeleton development. DARPA allocated $50 million for a five-year project to develop working exoskeletons for military applications. Japanese companies have also been working on developing working exoskeletons for commercial use, particularly to assist disabled and elderly people in functioning normally (in walking, climbing stairs and carrying loads).

Both efforts have reported successful exoskeleton development. The DARPA-funded projects at the University of California at Berkeley and at the Sarcos Research Corporation in Salt Lake City were reportedly ready for field demonstrations. Japan has the HAL-5 (the fifth-generation exoskeleton system called the Hybrid Assistive Limb or HAL). The HAL system is a full body suit aimed at helping people with degenerated muscles or people with brain or spinal cord injuries to function without human assistance.

These developments are slowly resolving the obstacles that have kept exoskeletons on the drawing boards for years. Sooner or later, there will be more than mere exoskeleton prototypes.

For more information on body armor, visit the Body Armor page at the Liberty Lib.