A wearable robot

by Paul Curzon, Queen Mary University of London

Beetles are one of the most prolific species on the planet. As the famous geneticist J.B.S. Haldane is supposed to have said: God has an inordinate fondness for beetles. One of the reasons they are so successful is that, unlike us, their skeleton is outside their body, not inside! This kind of skeleton is called an exoskeleton. Humans are now trying to get in on the act. In the computer science version exoskeletons are robots that you wear.

Animal shells

All sorts of animals have evolved all sorts of different exoskeletons. We call the big ones shells. Many insects, like beetles, have exoskeletons. So do crabs, scorpions, snails and clams. Tortoises are particularly interesting as they have both an internal skeleton, like us, and a shell too.

Animals use exoskeletons for lots of reasons. Most obviously it protects them from predators. It can also help stop them drying out in the sun, and stop them getting wet in the rain. They are used by some animals for sensing the world, and help animals like locusts to jump. Some tortoises and armadillos use them for digging and other animals use them to feed. It's not surprising, with so many uses that there are a lot of them about.

Human shells

Generally, exoskeletons seem like a pretty good idea! So it's not surprising that we humans want them too. A suit of armour is actually just a simple version of an exoskeleton designed to protect a knight from 'predators'. It's not much different to a tortoise protected inside its shell. The difference to the ones humans make now is our modern exoskeletons are powered and controlled by computers. They really are a robot you wear. They react to your movements.

As with animals' shells, powered exoskeletons help humans do all sorts of things, not just act as armour. By being powered they give us extra strength, allowing us to lift weights far heavier than we could otherwise, and can turn our small movements in to larger ones. That means they can, for example, help people who have problems moving about to walk (see 'The Wrong Trousers') or help nurses lift patients in and out of bed. They are used by surgeons to do operations when they are in a different place to the patient, removing the shakiness of their hands, and by rescue workers working in dangerous situations. There are even ones designed to help astronauts exercise in space. They make movement harder rather than easier to force them to exercise despite the lower gravity.

All in all, copying beetles, but with our own computing twist, seems like a pretty good idea.