Ryan Black

Zhenan Bao, PhD, thinks skin is taken for granted . There’s no context given for that quote, but it might be beside the point: “It’s a complex sensing, signaling, and decision-making system,” the Stanford University professor said of the human body’s largest organ.Bao and her colleagues want to replicate how skin behaves—how it stretches, repairs itself, and detects sensations. And they just published a study in Science that documents their creation of an artificial neuron, which they say is a major step towards that goal.The development they put forth looks more like an RFID sticker than it does skin, but the small, flexible patch is loaded with electronic sensors. Biological nerves work by funneling a series of nerve-ending stimulus to a single neuron once the signals reach a certain pressure threshold, and then passing that feeling up the line all the way to the brain.The patch mimics that phenomenon (they call it a “bioinspired flexible organ”), featuring a pressure sensor that increases voltage when touched, sending those signals to a ring oscillator that translates it into a string of electrical pulses, which then travel to a synaptic transistor that translates those pulses based on the combination of the amount of pressure and the length it’s applied. It allows researchers to detect where the sensor is being contacted and the nature of the contact being made—and they were able to detect a braille pattern using it.Even more fascinating (and somewhat creepy), they were able to make a severed cockroach leg flinch when its former host was equipped with the patch and the leg was hooked up to a corresponding electrode.The elements of the artificial neuron are all relatively cheap. Were many of them to be combined, artificial neurons might someday help enhance integration of prosthetic limbs or even, quoting Stanford’s statement, “give robots some type of reflex capability.” The science is still burgeoning, however, and the authors note that challenges still remain, like creating the ability to interface with the brain—as artificial skin would have to—or to detect sensations like temperature.