This is a question with many different answers. It depends on which part of nature you are talking about and who is asking the question.
In short, an exoskeleton is an external support for the body.
‘Exoskeleton’ is a word borrowed from the animal world, where exoskeleton refers to the outer shell/skin/carapace of invertebrates such as insects. Think of a typical beetle. Its hard outer shell is an exoskeleton.
When we talk about humans, the word ‘exoskeleton’ is used to refer to various types of devices that are worn to perform different tasks. They are also called exoskeletons, exosuits, exoskeletons and more, depending on what they look like and how they are used.
ASTM (formerly the American Society for Testing and Materials) defines ‘exoskeleton’ as ‘A wearable device that amplifies, enables, assists and/or enhances physical activity through mechanical interaction with the body.’ The Exoskeleton Report, another organisation in the United States, has modified this definition slightly by adding that an exoskeleton can also resist the body's movement. This could be, for example, a suit for astronauts, who need resistance to maintain muscle mass while in space, or a knee brace that absorbs vibrations and shocks during slalom skiing.
It seems that some experts would say that an aid that only stabilises a joint, typically a knee brace with plates on the side, does not qualify as an exoskeleton, as it does not add power to the body, but there are some grey areas and divided opinions about exactly what an exoskeleton is.
To better understand what an exoskeleton is, it may be helpful to look at some examples of what an exoskeleton is NOT, or at machines and equipment that cannot be called ‘exoskeletons.’
A human-controlled robot is also not an exoskeleton. Even though the robot is used to help a human perform a task, it is not attached to the body.
A human-controlled robot is also not an exoskeleton. Even though the robot is used to help a human perform a task, it is not attached to the body.
An exoskeleton is something between a smartwatch and a stand-alone robot. It can be anything from a glove that helps the hand perform work or a support device that provides power to the legs when walking uphill, to a full-body suit that has motors at several of the wearer's joints.
Exoskeletons can be with or without power sources such as motors, pumps, batteries, etc. ‘Active’ exoskeletons have such power sources, while exoskeletons without them are called ‘passive’. Passive exoskeletons often use elastic or springs to store energy from part of the movement, and then return the energy in the opposite movement.
There are many different types of exoskeletons, and this is a rapidly growing field, so new types and models are constantly coming onto the market. The various exoskeletons are used in many different industries and sectors, such as medical rehabilitation and physiotherapy, sports and outdoor activities, the military, agriculture, logistics and transport, the construction industry (carpenters, electricians, painters, fitters, etc.), car repair shops, removal companies and factories, among others.
To summarise: An exoskeleton is a comprehensive term for various aids that are attached to each side of at least one joint on the body to reinforce and/or influence the movement of the joint mechanically. It helps the body to perform work and movements that would otherwise be more difficult or impossible. To learn more about the different types of exoskeletons available on the international market, visit https://exoskeletonreport.com/.