Exoskeleton, in contrast of endoskeleton, is a general term to describe various external anatomical features that support and protect animals' bodies. Many invertebrate animals such as insects, crustaceans and shellfish have exoskeletons. Without scales, shell or a thick fur coat, human invented armour which resembles exoskeleton in its protective function.

Contents

1 Biological exoskeleton 1.1 Types of exoskeleton 1.1.1 Chitin 1.1.2 Calcium compounds 1.1.3 Silica 1.2 Comparative anatomy 1.3 Evolution 1.4 Molting 2 Human exoskeletons 2.1 Exoskeletons in history 2.2 Exoskeletons in medicine 2.3 Exoskeletons in science fiction 2.4 Exoskeletons in modern and near-future technology 3 External links

Biological exoskeleton

Types of exoskeleton

Chitin

• Arthropods
  • Insects
  • Crustaceans

Calcium compounds

• Corals
• Mollusks

Silica

• Radiolaria

Comparative anatomy

Evolution

Molting

• Moult

Spiders, for example, or lobsters, have tough outer shell systems which provide rigidity and shape to their bodies.

The types of animal that have exoskeletons are molluscs and arthropods; their exoskeleton gives them a rigid support, and protection from damage. In exchange, the exoskeleton will interfere with the growth of the animal. To overcome this, arthropods go through a process called moulting. Through this process, 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.

Human exoskeletons

Exoskeletons in history

Medieval armour (in the case of mounted knights) furnishes an example 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 used to describe the field dealing with orthoses, their use and manufacturing.

A limb "prosthesis" (plural prostheses)is a device that substitute a missing part of the limb. If the prosthesis is a holow shell and self-carrying, it is exoskeleton. 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 used to describe the field dealing with prostheses, their use and manufacturing.

Exoskeletons in science fiction

Science fiction authors perennially utilize the idea of personal self-powered exoskeletons, usually referred to as powered armor or, in Japanese anime and manga, mecha. Examples include the loaders used to enable dockyard workers to move heavy weights in Aliens (1986) and the Armored Personnel Units seen in Matrix Revolutions (2003). 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 some are derived from biological evolution, 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.

Exoskeletons in modern and near-future technology

In early 2000s a number of companies and research centres has developed first practical models of human exoskeletons. One of the main uses for them 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 combustion engine , batteries or, potentially, fuel cells. Another area of application is medical care, nursery 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.

In the future exoskeletons are expected to become ubiquitous in military and police, built in nanotechnological combat clothes. Later on they will undoubtedly find their civilian uses. However they will have to compete for adoption with another approach — surgically and genetically enhancing the human body itself by use of artificial bone s and muscles.

External links

• Video, images and articles about the Bleex exoskeleton project http://bleex.me.berkeley.edu/bleex.htm

• Wired article about the power-suit weighlifting championship http://www.wired.com/wired/archive/13.01/ironmen.html?tw=wn_tophead_4