Of course, we’re not there yet. But what does Salvia think will take us 50 to 100 years to nail down? He was good enough to break it down: “A system like this needs a few key technologies: 1] an ability to sense signals from Matt's body (from his nervous system or perhaps his skeletal muscles) 2] environmental sensors (to detect things like acceleration, position, strain, rotation, etc.) 3] a lot of computational power to interpret those signals 4] motors and actuators to drive the limbs and 5] a high-density energy source to power items 1]-4]. Of these 5 items, the first one and the last one would likely be the hardest to develop.”
“Sensing Matt's intended motion can happen in a variety of ways,” Salvia says. “Researchers have shown that they can read motion-related instructions directly from a person's brain using electrodes surgically inserted under the skull. However, the data rate and accuracy from such a system is very poor. For example, if you wanted to drive a robotic finger with your thoughts and have it type a message for you on a keyboard, you would be hard pressed to type a word per minute, and that word would probably have a lot of typos.” This is a key area that separates Damon’s “Hulk suit” from what we have available today. But Salvia also pointed out that today’s suits require extensive physical therapy. For example, if Damon’s character would need years of practice before he could run and jump as he does in the trailer. But there are other potential methods for the brain to communicate with the exoskeleton.
“Other options would be to sense the signals going to Matt's muscles either at the spine or closer to the muscles themselves. While I have heard of research along these lines as well, I'm less familiar with the pros/cons of the approach,” Salvia allows. “Finally the system could directly sense the contractions of Matt's muscles and then act to augment his strength. I'm not familiar at all with technology like this, but with hundreds of implanted strain sensors it would be theoretically possible.”
He goes on: “Environmental sensors for acceleration, rotation, etc. already exist and are definitely not the limiting technology. The required computational power isn't trivial (you'd probably need something akin to today's supercomputer), but at the rate that the industry is improving we should be there in a few decades. Also, actuator technology probably wouldn't be a limiting factor assuming that you have sufficient energy to drive them. Which brings us to the question of a power source.”
The power source is where an effective exoskeleton suit demands major technological advancements. In the film, the hulk suit’s battery life is never brought up. But in real life, Salvia declares, “We would need a huge breakthrough in battery technology to be able to store and deliver the kind of power necessary to move Matt's arms and legs with enough strength and speed to justify his cyborg addition. Unfortunately, battery technology is advancing very slowly. Right now the highest density energy sources that we have are chemical fuels like gasoline. Converting those fuels into useful electrical or mechanical energy requires an engine--something usually not known for its feather-like weight (not to mention heat, noise, etc.), so it would be really inconvenient to carry around on one's back. Other options like fuel cells have their own limitations, but maybe they'll get there some day.”
To see where we are with exoskeleton technology, Salvia offered this video which uses Iron Man 3 as a jumping off point to discuss exoskeleton suits.
Elysium opens everywhere this weekend.