The Eight Million Dollar Man

The Eight Million Dollar Man

How the story of an amputee’s bionic leg can help you to inspire your budding robotics experts

Although bionic arms have been around for a few years, the idea of a mind-controlled robotic limb is still pretty amazing!  The latest story of an amputee using a high-tech prosthetic leg provides the perfect opportunity to introduce your students to the science behind robotics.

Researchers from the Rehabilitation Institute of Chicago have taken a big step forward (horrible pun - sorry!) by developing a new generation of prosthetic legs.  They've equipped amputee Zac Vawter, who lost his leg in a motorbike accident, with a motorised, computerised limb that mimics the movement of a real knee, ankle and foot.

AA roboleg

Zac Vawter becomes the first person with a bionic leg to climb one
of the world's tallest skyscrapers (c) Associated Press Photos

In order to test the new leg, Mr Vawter set off on a challenging 103 storey stair-climb to the top of one of Chicago's tallest skyscrapers.

Have a look at this video to see the bionic leg in action:

As the NY Daily News reported, testing a robotic leg in this way isn't entirely safe - if it had failed then Zac Vawter could have tumbled back down the 2,100 stairs he had been walking up.

Thankfully, the public demonstration at the annual stair-climbing charity event called "SkyRise Chicago" was a roaring success.  Vawter told reporters, "Everything went great, the prosthetic leg did its part, and I did my part."

What's the science behind the headline?

Bionics (also called biomimetics - imitating life) combines:

  • biology
  • neurology
  • physics
  • electronics
  • engineering

The muscles in the human body are controlled by electrical impulses sent from the brain and spinal column (for more details read our article about Frankenstein's monster and the real life experiments that inspired the story for more details).

Robotic limbs are designed to detect these electrical impulses from the muscles in the leg or arm of the amputee, and respond to them with the appropriate movement.

In the case of Zac Vawter, surgeons connected his nerves that would have controlled his lower leg to his hamstrings.  The hamstrings are the tendons just above the back of the knee and are part of the group of muscles that bend our knees.

Anatomy Hamstring

With the nerves attached in this way, the electrical impulses that Zac Vawter's brain sent when he thought about climbing the stairs were detected by the bionic leg.  The motors, belts and chains in his leg then synchronized the movements of its ankle and knee.

This amazing breakthrough is part of an $8 million project funded by the U.S. Department of Defense which involves four major US universities, including the Massachusetts Institute of Technology (MIT).

It is hoped that the project will lead the production of mind-controlled prosthetic legs that will change the lives of many lower limb amputees from injured soldiers to accident victims.

For some ideas of how to include robotics in your science lessons have a look at the following sites:

If you know of any other resources, lesson plans, videos or ideas please let us know using the contact form and we can add them to the site.