The brain is a very poorly understood structure with thousands of different cell types and billions of cells networked together. The pharmacological approaches to cognitive and emotional modification dope the whole brain and frequently produce unintended consequences he said.
The ability to use transgenic modification to add light sensitivity to brain cells would then allow individual neurons to be switched on and off. Although far-fetched it would be significant aid to understanding how the brain works, a key step to producing well crafted repairs to cognitive and emotional conditions.
What is known, Herr said, from work done in 1996 and 2005 is that such techniques as deep brain stimulation using magnetic fields can relieve suicidal feelings by altering activity in very specific regions of the brain.
Herr referenced John Donahue of the Department of Neuroscience at Brown University (Providence, Rhode Island) and his group's work on implanted cortical arrays where slivers of silicon with 100 contacts are attached to neurons in particular region of the brain.
"It is used for cursor control and provides very good 2-D control," he said over a video of a patient that had his spinal cord severed by an attacker with a knife and lost all ability to move below the neck. "Neural implants demonstrate the extreme plasticity of the brain," Herr said referring to the brain's ability to accommodate a prosthesis and adapt to it positively.
Biological tissues are also highly promising to work with as muscle, nerve and skin cells can each be encouraged to grow and attach to appropriately fashioned materials and mechanical structures.
Herr gave the example of electronic interface that could, in theory by sited next to a cut nerve stump to create a bidirectional peripheral nerve interface. In this way the nervous commands can be sent biomechatronic limbs and joints and important feedback sensations can be injected back into the nervous system.
Machines could be mechatronic or they could be synthesized biological systems or hybrids of the two. Engineers will need to consider which is best skin or polymer, alloy or synthetic bone.
Herr showed a video of a synthesized agglomeration of skin and muscle showed that was effectively a biological machine that swims in sea of its own food; glucose and oxygen. Herr even held out the prospect of tissue engineering that could produce food: "The 3-D printing of food in a very efficient process."
And with much of this cross-fertilization definitions become blurred. Biomechatronics can help with the creation of limb extensions and it can also help with the creation of exoskeletons. And what is the difference between an exoskeleton and intelligent clothes. Herr showed examples of clothes that can adapt and move in response to commands or the environment.
"There are about 20 million leg and arm amputees in the world -- and then there is the shoe. It's crazy that in this day and age our shoes can still give us blisters," he said.
It was Herr's thesis that as the research world is full of amazing materials – such as shape memory alloys and electrolaminates that can adaptively change their properties – it is possible to create bionic prosthetics that better support the wearer. First must come a thorough understanding of the operation and control dynamics of the behavior in question such as walking.
"People are not disabled. They are a built environment. In the twilight years of this century we will eliminate disability," Herr concluded.
DESIGN West is organized by UBM Tech, the publisher of EE Times and EDN.