Lab-made artificial skin may enable people with prosthetic limbs to regain their touch or tactile sensation, according to researchers.
In the new study, the researchers were able to send an electric pulse to specific brain cells in mice, which resulted in preceiving touch sensation.
The artificial skin is made out of synthetic rubber that is extremely sensitive because of its micro-scale pyramid structures. Carbon nanotubes (CNTs) – cylindrical carbon molecules that are able to conduct electricity – were placed on the flexible synthetic rubber to generate a series of pulses when the material was touched.
The way in which the pulses are sent to the brain cells are similar to how human skin touch receptors send sensations to the bran, the researchers said.
“We were able to create [a system] very similar to biological mechanical receptors,” Benjamin Tee, a scientist at the Agency for Science, Technology and Research in Singapore and lead author of the paper, said.
In the study – published October 16 in the journal Science – the researchers connected the artificial skin to a circuit that was connected to a blue LED light (light-emitting diode) because they wanted to see whether the synthetic skin was able to generate electric pulses for the brain to respond to.
They found that when the skin was touched, the sensors would convert the pressure into electric pulses, which would then be sent to the LED that pulsed in response (flashing a blue light). The LED flashed faster when the pressure was higher.
Channelrhodopsin – a type of protein that triggers the reaction of brain cells to blue lights – was also added to the brain cells of the mice. With the help of channelrhodopsin, the LED light acted like skin receptor cells. A signal was sent to the brain as the light flashed, to indicate that the synthetic skin had been touched.
The area of study which uses light to stimulate brain cells is called optogenetics. This particular method is more advantageous than other technologies in which the neurons are stimulated through electrodes attached to the brain tissue, because it can use higher frequencies. The way in which receptor cells send specific signals to the brain can be more accurately recreated through higher frequency stimulation.
Image Source: discovermagazine