Though prosthetics have come a long way towards enabling people who have lost their limbs to fully function, they still lack in certain areas like fine motor skills and the sense of touch. Now, researchers at the University of Glasgow have developed new technology that could remedy the latter.
A team from the Glasgow School of Engineering has?developed artificial skin that would allow amputees to regain their sense of touch when using a prosthetic. The prototype involves using a polymeric protective layer over the prosthetic¡¯s surface, that sends back pressure and temperature signals to the wearer. For example, someone wearing this prosthetic could pick up a cup of coffee, and would be able to feel the grain of the ceramic as well as how hot the mug is.?
The problem these researchers, headed by Dr Ravinder Dahiya, faced is that such a device needed its own power source, making it necessary to also attach a battery pack to the robotic arm. Of course, this made the prosthetic bulky and unwieldy. The solution then, was to develop a version of the touch-sensitive layer that could power itself.?
As such, the team began experimenting with graphene, a material that remains transparent and flexible while also being incredibly durable. Using this, the researchers were able to make a new protective layer that was also capable of converting solar energy, 98 percent of the light hitting it to be exact. They did this by layering the graphene over a set of solar cells underneath the ¡°skin¡±, which would generate energy while in the sun and power the wearer¡¯s sense of touch.
Ravinder Dahiya with his prototype prosthetic
However, the researchers believe they still have a lot of improvements to make to the prototype. The device is still too bulky, so the next step is to miniaturise the technology further, in order to bring the prosthetic¡¯s weight closer to that of a real human hand. The team is also researching a way to store the solar energy converted in a light-weight battery pack within the device. Doing that would give the wearer the full experience of a mobile, sensitive hand, without worrying about when it will run out of power.
While the technology has been designed with amputees in mind, it could also eventually find its way to applications in robotics. A touch-sensitive skin could give a huge boost to the development of caregiver robots. With a sense of touch feeding back data, these bots could exercise restraint when dealing with infants, the old, or infirm, while still allowing them utilise more strength when say, picking up and moving household objects.
Images courtesy University of Glasgow