The human skin is the body’s largest organ. It also provides one of our most important senses: touch. Touch enables people to interact with and perceive objects in the external world. In building robots and virtual environments, though, touch has not been the easiest feature to translate compared to say, vision. Many labs are nonetheless trying to make touch happen, and various versions of artificial skin show promise in making electronics (like the ones powering prosthetics) smarter and more sensitive.
A study out this week in the journal small presents a new type of artificial skin created by a team at Nanyang Technological University in Singapore that can not only sense direct pressure being applied on it, but also when objects are getting close to it.
[Related: One of Facebook’s first moves as Meta: Teaching robots to touch and feel]
Already, various artificial skin mockups in the past have been able to pick up on factors like temperature, humidity, surface details and force, and turn those into digital signals. In this case, this artificial skin is “iontronic,” which means that it integrates ions and electrodes to try to enable sense.
Specifically, it’s made up of a porous, spongy layer soaked with salty liquid sandwiched between two fabric electrode layers embedded with nickel. These raw components are low-cost, and easily scalable, which the researchers claim makes this type of technology suitable for mass production. The result is a material that is bendy, soft, and conductive. The internal chemistry of the structure makes it so that when there is pressure applied onto the material, it induces a change in capacitance, producing an electric signal.
“We created artificial skin with sensing capabilities superior to human skin. Unlike human skin that senses most information from touching actions, this artificial skin also obtains rich cognitive information encoded in touchless or approaching operations,” corresponding author Yifan Wang, an assistant professor at Nanyang Technological University, in Singapore said in a press release. “The work could lead to next-generation robotic perception technologies superior to existing tactile sensors.”
The design of the device also creates a “fringing electric field” around the edge of the skin. This resulting electric field can sense when objects get close and can also discern the material that the object is made of. For example, it can distinguish between a plastic, metal, and human skin in a small proof-of-concept demo.
As for use cases, the artificial skin can be put onto robot fingers or on a control interface for an electronic game that uses the touch of the finger to move the characters. In their experiment, users played the game Pac-Man, and navigated through electronic maps by interacting with a panel of the artificial skin.
