Artificial Skin Gives Prosthetic Limbs A Sense Of Touch

Researchers have created a new artificial skin that, when used on prosthetic limbs, can give amputees a life-like sense of touch. The work was done by scientists at Stanford University, where they developed a prosthetic clothed in a type of electronic skin, one that can detect things like changes in pressure (e.g., touch). The touching is then transmitted off through nerve cells with light-activated ion channels.

This new artificial skin features printed organic circuits that are flexible and micro-structured resistive pressure sensors in addition to the aforementioned nerves. The pressure sensors in particular feature small pyramid-like structures on the surface — those are made from a carbon nanotube elastomer composite. With these, the skin can sense when it is being touched.

Conductance changes as the skin is touched, with the amount of pressure from the touch influencing that change. The organic circuit to which the sensors are connected, meanwhile, converts that touch signal into electric pulses. If the pressure gets harder, the frequency of the pulses increased.

From there, the electrical pulses are sent to an LED, and, finally, the LED's light is sent to an optical fiber that directly stimulates brain neurons — in this case, the brains of mice, which interpret the signal in much the same way they would a signal from skin. In the future, the researchers are looking to do similar work with other sensations, including heat.

SOURCE: Scientific American