Exoskeleton
Exoskeletons form structures encasing and protecting the body to which they belong.
Exoskeletons in non-human biology
\nSpiders, 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
\nExoskeletons in history
\nMedieval 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 contemporay science fiction
\nScience fiction authors perennially popularise the idea of personal powered exoskeletonss, examples including the loaders used to enable dockyard workers to move heavy weights in Aliens (1986) and the soldier-weaponry units seen in Matrix Revolutions (2003). In comic books, the superhero, Iron Man wears a suit of powered armor which has 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.
Exoskeletons in modern and near-future technology
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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 undoubtly 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 bones and muscles.
