Advances in robotics serve more than just getting your Amazon order in sooner. The great potential lies in the development of prostheses that look natural and function like real limbs; but even if they meet those requirements, they are not suitable for everyday use.
Because there’s one thing all these prostheses can’t imitate: touch. Someone who uses a mechanical arm can live a relatively normal life again, but it will never be the same without the sense of touch. It’s not just an emotional question: touch plays a very important role in our limbs, providing vital information.
When you pick up a bottle, you instinctively know if you have to keep squeezing your hand or if the force you are exerting is enough to keep it from escaping between your fingers, for example. It’s something we don’t think about on a daily basis, and it only reveals its importance when we lose it. Now a study by scientists at the University of Utah may have taken a big step toward regaining a sense of touch, even if we’ve lost our arm.
They have achieved this with a new prosthetic arm, called LUKE, and the development of a new type of “inclined electrode”, which serves as a bridge between the prosthesis and the sensory nerves and motors of the arm. Even if we lose an arm, these nerves continue to function up to the residual limb, and can give the sensation of the “phantom limb”.
Scientists have taken advantage of this to connect the prosthesis directly to the nerves using these new electrodes. That means going through an arduous surgical operation that involves attaching hundreds of electrodes to each nerve.
These electrodes are capable of recording the currents coming from the nerves, as well as stimulating them. In other words, they can receive “orders” to move the prosthesis, which in turn can send information to register the nerves. The important thing is that, thanks to this innovation, the system is able to stimulate nerve fibers in a very selective way; thanks to this it is possible to register and send very specific sensory and motor signals. That’s why its creators have named this arm LUKE after Luke Skywalker of Star Wars, who also wore a prosthesis since the end of the second film.
Although this is not the first project that claims to have created a prosthetic arm that “feels”, it is the first time such precision has been achieved, and opens the door for a prosthetic arm to feel exactly the same as the natural one in the future.