Stanford researchers led by Zhenan Bao have developed an artificial skin that can detect the slightest changes in pressure. The material was successful in registering the weight of small insects.
Previous attempts to make artificial skin were often done with very thin, continuous sheets of rubber or film. Sensors using this type of skin could not be made sensitive enough to detect tiny changes in weight. The innovation of the Stanford team was to craft a thin elastic rubber sheet into a grid of miniscule pyramids, up to 25 million per square centimeter, sandwiched between electrodes. The slightest change in pressure resulted in the compression and re-expansion of the tiny pyramids, which altered the electric flow and could be detected by sensors. By altering the shape of the pyramids, the scientists were able to change the range of sensitivity.
Caption: The sensor is sensitive enough to easily detect this butterfly positioned on a sheet of the sensors.Credit: Linda Cicero, Stanford University News Service
So far, the team has created a patch of ‘skin’ about seven centimeters across. It mimics both the pressure sensitivity and the response rate of human skin. In addition, it appears to be flexible enough to be used as a covering for a variety of surfaces.
Needless to say, there are myriad uses for such exquisitely sensitive artificial skin. Besides the obvious usage in prosthetics, the pressure sensitive system could also revolutionize robotic surgeries, create pressure-sensitive bandages, help athletes improve their grips…you name it!