The Online Encyclopedia and Dictionary







An exoskeleton, in contrast to an endoskeleton, is an external anatomical feature that supports and protects an animal's body. Many invertebrate animals such as insects, crustaceans and shellfish have exoskeletons. Lobsters, for example, have tough outer shell systems which provide rigidity and shape to their bodies.

Humans have long used armour as an artificial exoskeleton for protection, especially in combat. Exoskeletal items are also used for medical and industrial purposes. Human exoskeletons are a feature of science fiction writing.


Natural exoskeletons

Types of exoskeletons


Calcium compounds



An exoskeleton may interfere with an animal's growth. To overcome this, arthropods go through a process called moulting in which they shed their exoskeleton and replace it with a new, larger one.

Excellent as a principle of defence, exoskeletons may nevertheless cause problems where entities carry an excessive weight to surface-area ratio; or whenever organism growth requires an enlarged exoskeleton.

Artificial human exoskeletons

Exoskeletons in history

Medieval armour (in the case of mounted knights)is not load-bearing, but furnishes the appearance of an artificial human exoskeleton. Modern motorists use automobiles as temporary protective exoskeletons in harsh traffic environments.

Exoskeletons in medicine

An "orthosis" (plural orthoses) is a device which attaches to a limb to support the function or correct the shape of that limb. "Orthotic(s)" is the term for the field dealing with orthoses, their use and manufacturing.

A limb "prosthesis" (plural prostheses) is a device that substitutes for a missing part of the limb. If the prosthesis is a hollow shell and self-carrying, it is exoskeletal. If internal tubes are used in the device and the cover (cosmesis) to create the outside shape is made of a soft, non-carrying material, it is endoskeletal. "Prosthetic(s)" is the term for the field dealing with prostheses, their use and manufacturing. PBS

Exoskeletons in modern and near-future technology

Human exoskeleton by Sarcos
Human exoskeleton by Sarcos

In the early 2000s a number of companies and research centres developed the first practical models of human exoskeletons. One of the main uses is enabling a soldier to carry heavy weights (50–100 kg) while running or climbing stairs. Most models use a hydraulic system controlled by an on-board computer. They can be powered by an internal combustion engine, batteries or, potentially, fuel cells. Another area of application is medical care, nursing in particular. Faced with the impending shortage of medical professionals and the increasing number of people in elderly care, several teams of Japanese engineers have developed exoskeletons designed to help nurses lift and carry patients.

Commercially-available exoskeletons are expected by the end of 2005 [1].

In the future exoskeletons are expected to become widely used by the military and police in the form of nanotechnological combat clothes. Civilian uses will no doubt be found later. However they will have to compete for adoption with another approach — surgically and genetically enhancing the human body itself by use of artificial bones and muscles.

Human exoskeletons in science fiction

Science fiction authors utilize the idea of personal self-powered exoskeletons, usually referred to as powered armor or, in Japanese anime and manga, mecha. Examples include:

  • The armour worn by Gray Fox in Metal Gear Solid
  • The loaders used to enable dockyard workers to move heavy weights in Aliens (1986)
  • The Armored Personnel Units seen in Matrix Revolutions (2003).
  • The novel Starship Troopers details the tactics involved with powered armor.
  • Standard issue battle armor in Joe Haldeman's book The Forever War is an exoskeleton using logarithmic force amplification.
  • Exoskeletal vehicles named "E-Frames" were one of the central aspects of the anime-inspired American action cartoon Exosquad.
  • In comic books, the superheroes Iron Man and War Machine, the supervillain Doctor Doom and countless others wear suits of powered armor which have the equivalent exoskeleton function.
  • Not all SF exoskeletons are mechanical, as modification of biological systems can produce similar strength, such as the Pak Protector in Larry Niven's Known Space universe, Jim Shooter's X-O Manowar comic book, and the Guyver anime series.
  • In Japanese manga Gantz, the characters wear wet suit like exoskeleton, which gives them enormous strength and provides protection.
  • Biological suits known as skins are mentioned in Peter Hamilton's Fallen Dragon.
  • In the Battletech universe, genetically engineered Clan soldiers are bred for strength and other qualities to wear Elemental powered armor. Elemental armor also provides advanced medical technologies to keep the wearer alive in case of severe injury or trauma during combat.
  • Unsurprisingly, exoskeletons have surfaced in many video games, usualy because thicker types of armor must require some mechanical power source. Some examples would be certain marines from Unreal II: The Awakening and MAX Units from Planetside.
  • Many Japanese mecha anime also have humans controlling gigantic exo-skeletons, such as Escaflowne. Although many of these are not exactly exoskeletons because of their size, the main principle is identical.

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Last updated: 10-19-2005 17:20:34
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