The human hand has 17,000 touch sensors that help us in doing day-to-day jobs, sensing, and picking things up. The prosthetic hands or feet have no sensation in them.
Zhenan Bao, at Stanford with her research team is trying to invent materials for touch-sensitive prosthetics. Her vision is to create and develop some layer-like structure that would be able to sense pressure, process sensory data, and heal when cut. It is not far when we can link these prosthetics to nervous system that can deliver the sense of touch. Even before that the electronics skin would help amputees and burn victims do regular chaos like picking up delicate objects- and can possibly wipe away phantom limb-pain. Just like real skin, it should also be stretchy, light-weight, durable, and should able to self-heal.
Bao has been working an electronic skin since 2010. She also has to produce different chemicals for every electronic component. In place of silicon-flexible organic molecules, polymers, and nano-materials to be used.
Bao’s group is working on a human skin like structure stretchy material so that they can recover. Sometimes electronics materials are also mixed in the rubber. To give the sensation of touch the researchers mix in carbon, that is electrically conductive. When pressure is applied on the skin the voltage across the conductive rubber sheet changed. Covering these touch sensors with pattern of microscale pyramid improved touch sensitivity. It is said that depending on design the sensitivity will be as likely as our skin. The research team also prints transistors, electrical lead and other component on the rubbery skin to make it more sensory and stretchy.
Now Bao is working on another weird material that can be stretched more than human skin (around 100 times) without breaking. This polymer also heals when cut, without the use of any heat or other triggering materials. Whenever electrical field is applied it is programmed to either expand or contract. The team is also working with semiconductors and other electronics materials. It is now to be seen when the amputees can touch and feel their loved ones and can be benefited by this invention.