By E. Paul Zehr
When I was writing the book “Inventing Iron Man: The Possibility of a Human Machine” I took a real hard look at how Iron Man’s suit of armor could actually work with all that human biological hardware inside of it. The first step was was—in homage to Coleridge—to employ some willing suspension of disbelief—if the technology for Iron Man’s suit of armor existed, how could you link it up to a human body?
So I did a lot of thinking about Iron Man as a neuroprosthetic. The fanciest, jazziest, most ambitious neuroprosthetic ever conceived, in fact.
And that’s when I came across the Iron Man “Extremis” story arc that Warren Ellis penned and Adi Granov illustrated . I came across it and read it and I went all slack-jawed. Here was a comic book writer who had identified the exact way I had by looking at the problem through the lens of modern neuroscience. It was very cool. But at the time the problem with the concept was linking the robotic suit of armor to the nervous system of Tony Stark. How do you interface that with the brain and spinal cord?
At the time I looked at the problem in a very conventional way. Brain machine interfaces with the highest fidelity typical involve implantation of electrodes into the brain itself. So that’s how I conceived of it. An electrode array would be implanted into the brain and the spinal cord and then used to control the Iron Man suit. The trick is that to fully integrate the suit with the brain would mean many implants into the central (brain, spinal cord) and peripheral (nerves in arms and legs) nervous system.
This worked as a conceptual explanation but I wasn’t very happy with how this might work in practice. Recently, I was doing a talk for a group of high school students visiting campus, I thought about this again. I was using Iron Man as a metaphor for neuroscience and neural plasticity and suddenly realized a much better way to do this. A way that’s actually a lot closer to the Extremis interface itself.
The problem is how to create an interface between the suit of armor that will come in contact with the skin and the finely branching terminal projections of the nervous system that lie just underneath that skin? The answer is…enter the Mandarin! Umm, regenerative medicine and tissue engineering, I mean.
Even though the term “tissue engineering” wasn’t used until 1987, Francois Berthiaume and colleagues at Rutgers in New Jersey suggest that this field began way back ~3000 years ago when skin grafts were performed in India. More recently, composite living skin was created in 1981. Now tissue engineering has impacted on skin, cornea, liver, pancreas, cartilage, heart, kidney, and, with particular relevance here, neurons.
The way to integrate the Extremis concept for Iron Man with modern neuroscience is to create an interface through the skin using the basic concepts of regenerative medicine. The gist of this is shown below. Tissue would be extracted from the person for whom the interface is being created, the appropriate cells (neurons in this case) would be isolated and cultivated. In vitro the process would continue with proliferation of the neurons but in a targeted way using a tissue scaffold to direct and shape the growth. After shaping by mechanical and electrical stimulation, these artificially integrated tissues would then be implanted back into the user.
Voila. You now have the makings of an interface that could be used to link to the user. Of course you then have to add the autonomous robotic Iron Man suit of armor, ensure that the tissue continues to grow in a targeted way to connect to the natural nervous system of the user, and hope the biotech interface you created is accepted by the immune system of the user. Oh yes, and do a bunch (years) of training.
But those are considerations for another day. For now, when you read an Iron Man comic book or graphic novel, or watch the latest installment of big screen Iron Man, just marvel that the real science needed to connect that tech to human biology is rapidly advancing. The future really is now.