Image courtesy of Dr. Kazerooni, University of California at Berkeley

Imagine that you are in your room and you would like to move your bed. It's likely your bed is much too heavy for you to lift and move by yourself. So, without someone to help you, you are stuck. But what if you could slip into something called an exoskeleton, and it would amplify your strength by a factor of 10. Without the exoskeleton, you might be able to lift 25 pounds easily. With the exoskeleton, you can lift 250 pounds easily. Suddenly, moving your bed around all by yourself is incredibly easy.

The thought of a strength boost like this is what makes the idea of exoskeletons so exciting, and not just for moving beds around. Imagine a soldier on a battlefield who needs to lift a 500-pound missile. Or imagine a worker in a warehouse who would like to put a pallet on a shelf without using a forklift. Or imagine a construction worker who would like to be able to position a heavy steel beam so he can bolt it in place. Many people could use an exoskeleton in lots of different situations.

So what is an exoskeleton? It's a metal framework that you strap onto your body. The exoskeleton frame is able to bend and move the same way you are. For example, the legs of the exoskeleton have joints that bend just like your knees and ankles bend. The thing that makes an exoskeleton so powerful is a system of actuators and sensors. For example, an exoskeleton might have electric motors at each joint. When you move your knee, the exoskeleton frame senses the movement and then amplifies it by sending power to the electric motor for the knee. So the exoskeleton frame moves in exactly the same way your body moves, but amplifies your strength.

Photo by Zade Rosenthal TM & ©2007 Marvel ©2007 MVLFFLLC. All rights reserved. With characteristics like superhuman strength, full-body, weapon-proof armor and flight-enabling jetboots, it's possible Iron Man inspired today's exoskeleton-making scientists.

People have been imagining exoskeletons for more than 50 years. But exoskeletons haven't really taken off for two reasons. First, it takes a lot of computer power to get an exoskeleton to match a person's movements that closely. Second, it has taken some time to create motors (and other actuator systems like hydraulics or pneumatics) that are both small and strong. Now that both these problems have been solved, we are seeing more and more exoskeletons coming out of laboratories. Who knows, maybe someday you'll be able to buy one at a hardware store.

Exoskeletons and Insects When people hear the word exoskeleton, they often think about insects or crustaceans. If you have ever eaten a crab or a lobster, you have seen an exoskeleton up close. Lobsters and crabs are sort of like big underwater insects. The hard outside shell that covers the body and legs of a crab is the exoskeleton. The muscles are inside, and they attach to the exoskeleton to let the crab move. Crab and lobster muscles are tasty, which is why we crack the shell and eat the muscles. Some of the exoskeletons that scientists create for human beings might look a lot like insect exoskeletons. It's easy to imagine an exoskeleton that completely covers a person in a shell, kind of like a hard space suit. There are many potential advantages of a shell exoskeleton such as climate control and bulletproofing. But most exoskeletons being created right now are just frames; they're lighter and less expensive, and also easier to put on and take off.