Paul Zehr has spent the past few years doing what most comic-book fans can only dream of: making a scientific case for the creation of a real-life Iron Man suit.
Dr. Zehr, a neuroscientist at the University of Victoria, says the technology for building an armoured suit activated by brain signals that can command the device to move, leap in the air – or even fly – isn't that far off.
"It's about 20 to 40 years away," Dr. Zehr says.
But his new book, Inventing Iron Man: The Possibility of a Human Machine, is far from a blueprint for battling supervillains.
Instead, Dr. Zehr envisions a bionic suit designed to help humans recover motor functions after debilitating strokes and spinal-cord injuries.
"The fact that superheroes are so popular now makes them really good foils, or metaphors, for explaining these things."
Dr. Zehr started writing popular science books – including 2008's Becoming Batman: The Possibility of a Superhero – to give people a better understanding of how their bodies work, he says.
The Batman book was about taking training and human biology to the limit, whereas the Iron Man book is about "what happens if you try to amplify biology with technology."
Many components of the Iron Man suit invented by the fictional character Tony Stark, a superhero in the Marvel Comics universe, are already in the research and development phase, he says.
There's HAL, a "hybrid assistive limb," created by Japanese inventor Yoshiyuki Sankai. Consisting of a human exoskeleton, Dr. Sankai's "robot suit" can amplify arm and leg movements tenfold. Naturally occurring nerve signals on the surface of the skin send cues to a computer that activates small motors connected to the metal and plastic exoskeleton.The HAL suit can't fly, Dr. Zehr says, but "Rocket Man" can. Its inventor, the Swiss pilot Yves Rossy, flew over the Grand Canyon in May, 2011, using a jet-powered fixed wing strapped to his back. It took him eight minutes to complete the eight-kilometre flight.Dr. Zehr notes that the Iron Man suit featured in Hollywood movies doubles as armour in much the same way as the Kevlar-fortified suits used for bomb disposal, and the Nuytco submersible suits used in NASA training.
As for Iron Man's brain-machine interface, he says, software engineers and neuroscientists are still working out the kinks.
Nevertheless, rudimentary devices already allow people to control a wheelchair or move a cursor on a computer screen using electrodes attached to a headband.
In 2008 at the University of Pittsburg, researchers implanted electrodes into a monkey's brain that enabled it to move a robotic arm with its mind to feed itself marshmallows.
Last month at the same university, Tim Hemmes, a quadriplegic, made history by touching his girlfriend's hand using a robotic arm. Like the monkey, Mr. Hemmes had electrodes implanted in his brain. He practised six hours a day, six days a week for nearly a month to move the arm with his thoughts – an effort that underscores the limits of the technology so far.
Dr. Zehr points out that implanted electrodes are invasive and vulnerable to attack by the body's immune system. "We need better technology for accessing neurons in the brain."Another stumbling block to building an Iron Man suit is to find a sufficient power source, he adds. "It has to be small and light and really powerful, and those things don't go together normally."
Solutions may come with advances in nanotechnology, he says.
In his books, Dr. Zehr packs course loads of neurology, physiology, robotics and biomedical engineering under the superhero cloak. The sci-fi formula has made him something of a cult figure at San Diego and New York Comic Con events.
But Dr. Zehr emphasizes there are ethics to consider in the making of a brain-operated human exoskeleton. What if a real-life Iron Man suit fell into military hands? And what's to stop someone from hacking into the wearer's brain, just as the villainous Ivan Vanko took over an air force commander's armoured suit in movie Iron Man 2?
The inventors of HAL and the jet suit have gone on record saying they do not want their devices to be militarized, Dr. Zehr says. But he adds that several industry groups may be piecing together similar technology for such use.
On a less ominous note, state-of-the art prosthetics could shift the focus on training and human physiology in professional sports. That's already happening, Dr. Zehr says, pointing to Oscar Pistorius, the South African sprinter and double amputee whose blade-like artificial lower legs enable him to compete against able-bodied runners.As the Six Million Dollar Man becomes a reality, technological advances such as brain-machine interfaces have the potential to change what it means to be human, he suggests.
"As a society," Dr. Zehr says, "we should probably think about some of the ethical or moral implications of all this technology now."