Coming Into Their Own Skin: Synthetic Skin for Prosthetics

   As you are reading this post, you have probably used your hands to type in the address and the mouse to control where you are on the screen. For people without limbs, this would be the biggest challenge because they do not have the appendages to perform these tasks. Some, the reason is that they cannot afford a prosthetic. For the lucky few who are able to afford a prosthetic, the do not have the motor skills comparable to a normal hand and they do not have any sensory functions like human skin.

Aadeel Akhtar and his team of researchers at the University of Illinois Urbana-Champaign were able to create a myopic hand at a low cost so the common man with a hand amputation can afford it. Akhtar was able to do this through the magic of 3-D printing and common items that anyone can find off the shelf. Also, he was able to create it to function like a normal hand with the capability to be controlled by the user by their brain by connecting electrodes to the user's nerves and muscles. Also, the hand is not as heavy as other prosthesis because this particular device connects not solely to the nerves and muscles, like other prosthesis do, but it also connects to the skeletal system just like a normal hand does. Thus, the load on the arm is lightened and the hand would be easier to use. While this is a significant advancement in the bio-medical engineering world, there is an issue with the fact that there is no sensory capability with the hand. Meaning, there is no way for the user to feel what they are doing, which would render some activities difficult because they have no feeling where things are. Is it even possible for a mechanical thing to feel pressure, temperature, and motion just like the human skin can?

Some new research would answer YES! to that question. Researchers under Hyunhyub Ko at the Ulsan National Institute of Science and Technology have developed a new type of "electronic skin" for prosthesis. This new kind of skin can detect directionality of motion and pressure. The new skin is made up out of tiny domes, much like how our skin is set up. When there is pressure or motion from anywhere around it, the domes cave in and misshape, exactly how human skin works. The domes' contorting is what creates the effect of the sense of motion. Readings from the contorting of the domes are processes through electrodes and sent to the brain to process what the motion is. This ability makes it possible to feel textures of objects and how much pressure is needed to pick something up, a crucial skill needed for prosthesis. It is Ko’s hope for this new kind of synthetic skin and prosthesis to be able to work in tandem in the future.

This new artificial skin created by Ko and Akhtar’s new low-cost myopic hand could become the new dynamic duo in the medical world. With Akhtar’s hand having more and better motor function with a lesser cost and Ko’s artificial skin being able to sense direction of pressure, they can create a prosthetic hand that is almost identical to a normal human one. The new skin can sense textures and pressure, which is the missing piece to Akhtar’s hand. The skin enables users to feel how much pressure they are putting on the object they are grasping or able to touch and feel textures. Further research is necessary to determine how the electrodes would work together, but will be great assets to each other in the future and beyond.

Sources:

Akhtar, A., Bretyl, T., Nguyen, M., Slade, P. (2015). Tact: design and performance of an open-

source, affordable, myoelectric prosthetic hand. The International Conference on Robotics
and Automation.

http://www.sciencedaily.com/releases/2014/12/141210121405.htm

http://www.acs.org/content/acs/en/pressroom/presspacs/2014/acs-presspac-december-10-2014/new-electronic-skin-for-prosthetics-robotics-detects-pressure-from-different-directions.html