Super Sensitive Electronic Skin for Prosthetic Devices

Artificial skin with the ability to feel is a major research goal for engineers working on improving prosthetic technology. Researchers in the past have created materials with sensors spread over a few square inches, but these have typically had a number of limitations.

One thing that causes many such electronic skins to be impractical is the complex wiring that is required to make hundreds, if not thousands, of independent sensors work together. The other issue is that by scaling up to make ever larger pieces of e-skin, vastly more signals have to be processed in real time.

Now, researchers at the National University of Singapore have developed an e-skin that works using only a single electrical cable that connects all the sensors together, and the skin is more responsive than anything similar developed in the past.

The team’s Asynchronous Coded Electronic Skin (ACES) is a sort of synthetic nervous system that can be integrated into other devices, including prosthetic arms, clothing, and assistive devices. Having only one, relatively strong cable makes it resistant to damage as compared with relying on hundreds of very fine wires. If the lone cable is broken, it should be pretty easy to find the fault and solder it back together.

The team claims that its system is 1,000 times faster than our very own sensory nervous system, with the ability to detect changes across multiple sensors within 60 nanoseconds. Moreover, the e-skin, when placed over different objects, can identify their texture, shape, and softness. This it does within about 10 milliseconds, which is nearly instantaneously compared with our reaction time.

“Scalability is a critical consideration as big pieces of high performing electronic skins are required to cover the relatively large surface areas of robots and prosthetic devices,” explained Asst Prof Tee, one of the research leads. “ACES can be easily paired with any kind of sensor skin layers, for example, those designed to sense temperatures and humidity, to create high performance ACES-enabled electronic skin with an exceptional sense of touch that can be used for a wide range of purposes,” he added.