Merging Man and Machine: A Science Café Experience

Cal Poly SU’s Science Café put on yet another educational presentation this afternoon at the Kennedy Library. The guest speaker, Cal Poly alumnus Russ Angold, discussed his work for Berkeley Bionics and their innovation of the “bionic suit”– or robotic exoskeletons for human use.

An exoskeleton is basically a robot, strapped along the back of the legs. It has joints that are powered by electricity, and sensors that allow it to step in synch with your body. The job of the exoskeleton is to bear weight–up to about 135 pounds–so that you don’t have to.

An exoskeleton is not a prosthetic or replacement limb. Instead, it works in harmony with the human body so that a person can safely carry weight while protecting their spine from stress. It has both military and medical applications, to be discussed below.

In his presentation, Angold demonstrated the use of his bionic suit. He strapped himself into it in under a minute and flipped the power switch. My instant perception was of the Iron Man from the blockbuster movie of 2008–the joints whirred as if they were alive, and Angold suddenly appeared to be the most powerful man in the room. Undoubtedly, we all believed for a split second that this engineer could thwart a terrorist cell, if called upon.

While these exoskeletons are not as advanced or flashy as Iron Man’s iconic suit, they are a step in a similar direction. Just as Tony Stark’s computer was synchronized with his body movements, so is the bionic suit. There are some physical limitations; for example, the exoskeleton cannot harness enough power to jump up a ledge, much less fly. However, it does provide the strength needed to carry a heavy load, and it does so without compromising the speed or energy exertion of the wearer.

So who is wearing this new robotic technology? The exoskeletons have two current applications: military use and rehabilitation for paralyzed patients. There are two distinct suits for each purpose. The military suit is called HULC – Human Universal Load Carrier. The medical rehab suit is called eLEGS.


Alarming statistic: more American soldiers are injured by the heavy equipment they carry than are injured by combat wounds. Angold and his company set out to fix this problem by designing an exoskeleton that would satisfy the military’s needs.

First, it must be able to hold up to 135 pounds, the maximum weight of a soldier’s backpack. Secondly, it must be self-powered so that it doesn’t increase the metabolic cost for the soldier to walk. Metabolic cost is the energy it takes to perform a task. Previous versions of the exoskeleton didn’t have powered joints at the knees or hips, so the machinery of the exoskeleton made it more costly to walk. The electric power reduces this biological cost.

Not all of the weight is supported by the HULC, only the vertical weight that is pressing down on one’s spine. The soldier still has to control the inertia and mass of the pack when starting, stopping, or turning. But the reduced spinal stress results in fewer injuries for those who serve our country.


Paralysis does more than just take away one’s ability to move. It also robs muscle strength and muscle memory. People hospitalized for paralysis literally forget how to move their limbs. eLegs can help remedy this.

A patient wearing eLegs uses handheld controls in the form of walking sticks to direct the exoskeleton’s path. The exoskeleton uses its battery power to lift their feet, allowing them to walk despite their weakness or paralysis. Now, paraplegics and quadriplegics don’t have to wait for their strength to return to start rehabilitation. They can strap themselves into the eLegs and practice walking every day. Their muscles grow stronger, faster, and muscle memory stays intact. Today, a pair of eLegs costs around $100,000. Angold expressed a desire to lessen this cost to one third of the going rate.

Resources to visit

Science Café Page

The Incredible HULC

Angold’s Company Homepage