Electronic skin breakthrough could make prosthetics “feel” real

Inspired by Luke Skywalker’s robotic right arm from the Star Wars original trilogy, a group of scientists from the National University of Singapore has developed ACES, short for Asynchronous Coded Electric Skin, an “electronic skin” with features similar to that of human skin and able to mimic the body’s peripheral nervous system.

ACES is composed of 100 small sensors which measure at around 1 sq cm (0.16 sq inch) in size. The electronic skin is capable of sensing and differentiating 20 to 30 textures, detecting objects, as well as feeling temperature, hardness and even pain in 10 milliseconds. The sensations gathered from the sensors are sent to an artificial intelligence (AI) “brain” which interprets the said readings. The process is 1,000 times faster than the human nervous system while retaining relatively high accuracy, scoring above 90 percent accuracy when reading Braille letters.

A paper published in the journal Science Robotics explained that ACES works by transducing tactile events into pulse signatures. The system is designed in a way that even if there are 10,000 sensors in a given system, the latency would still be relatively low (one millisecond) while at the same time retaining an ultra-high temporal precision of greater than 60 nanoseconds through the use of asynchronous transmission. The pulses coming from the sensor are then decoded and then compared to the existing temporal arrangement for each receptor’s signature.

Benjamin Tee, research team leader explained that people who use prosthetics experience difficulties as they are unable to feel what the prosthetics are able to hold as they are unable to gain a sense of touch, retaining the feeling of numbness. He also explained the difficulties of creating the “skin,” which when combined with AI algorithms would allow ACES to detect and identify them with relative ease.

Traditionally, humans need to slide their fingers or run an object against their skin to feel a certain texture. ACES, however, is able to detect different textures and roughness in just one touch.

Tee said that he drew inspiration from The Empire Strikes Back where in Luke Skywalker had his hand chopped off by Darth Vader and eventually gets it replaced by a robotic hand. In the scene where Luke gets his prosthetic hand attached, a medical robot tested if he was able to feel pain by pricking the hand. The scene was etched in Tee’s mind as a kid and eventually became an inspiration for him to science fiction into reality.

In a video posted at the World Economic Forum website, tests conducted on the sensor showed that it was able to quickly identify that a squishy orange ball squeezed against the sensors was soft and when a solid plastic ball was placed against it, the sensors identified it as a hard object, all of which done in a single touch.

Apart from their ongoing study with the electronic skin, the team has already developed patents of a self-repairing transparent skin that can “heal” itself when torn and has also developed a material that emits light meant for wearable electronic devices.