The iLimb is the most advanced bionic hand currently available, with five individually powered, multi-articulating fingers controlled by electrodes that are placed on the surface of the skin and are designed to pick up muscle signal, Karen Hakenson, a communications representative from Touch Bionics, told us. However, because it was designed to work with human nerves, all of this functionality initially was useless on the Bionic Man, she said. "The hand was designed to take a nerve signal from the human body, but of course we didn't have a nerve signal," she said. "We had to build electronics to fake a nerve so the hand could respond to the signal it was expecting."
Not all the parts on the Bionic Man were from manufacturers, however. Some, like the robot's shoulders, had to be custom built to suit the design goals of the robot. Shadow Robot undertook this challenge itself, constructing a shoulder out of aluminum, a type of plastic called delrin, and a series of 3D-printed parts. "We needed movement in the shoulder for reaching out and grasping something, and there wasn't a prosthetic shoulder that could move," Walker said.
The SynCardia Total Artificial Heart was used as the heart for the Bionic Man, pumping blood from each ventricle through the robot’s artificial circulatory system at 2.5 gallons per minute. The heart -- which is typically used as a temporary replacement heart for people awaiting heart-transplant surgeries, and then removed once a viable donor human heart is found -- is capable of all of the functions of a normal human heart. The company currently is working to certify the heart as a permanent replacement organ.
(Source: SynCardia Systems)
To enable this movement once the shoulder was built, the Bionic Man's designers used a pneumatic muscle running on compressed air to mimic a body muscle, giving the shoulder the range it needed to move backward and forward, Walker said. Another part that needed to be custom built was the robot's circulatory system for moving the fake blood that pumped from the heart.
Walker said he and his team realized this was expertise they didn't have and was a task better left up to a medical expert. They brought in Dr. Alex Seifalian from University College London, who had a more working knowledge of a human body's circulatory system than the robot makers, to build the part of the robot that would pump blood from the heart to its organs. Seifalian, professor of nanotechnology and regenerative medicine, constructed the system with a mixture of plastic piping and artificial blood vessels, Walker said. The completion of the circulatory system gave the Bionic Man the lifeblood and the real-life animation perspective the robot didn't quite have before. "When [Seifalian] filled it with artificial blood and turned the heart on, it was a pretty spooky moment," Walker said.
Indeed, all of this construction has left the Bionic Man with some uncanny human-like features. It can walk unaided on its prosthetic legs and talk using a triptych of technologies -- sophisticated chat bot called Eugene Goostman from Princeton Artificial Intelligence, speech recognition software, and a text-to-speech generator of the same ilk as the one used by Steven Hawking, according to Pope.
Because of the speech-recognition technology, the Bionic Man can have conversations with people, using the same colorful language humans sometimes use. "He was sometimes a bit rude and a bit sweary," Pope said. This is likely because the person programming the robot used colorful language in its conversations with the robot, which learned to speak through a combination of both custom programming and also mimicking other people, he said.
Thanks to advanced retinal prostheses from Second Sight and his custom-built shoulder, the Bionic Man could also locate and pick up objects, and even pour a drink, Pope said. In the end, Shadow Robot's Walker concluded that about two thirds of a human body can currently be replaced by the medical industry. "A lot of this technology is really surprisingly impressive," he said. "It has come a long way in the last 10 or 20 years."
An infographic on the website of the Smithsonian Channel shows the various artificial parts of the robot and describes their functions.