If you slip a tiny wearable device on your fingertip and slide it over a smooth surface like a touchscreen, you can feel digital textures like denim or mesh.
The device, designed by researchers at Northwestern University, is the first of its kind to achieve “human resolution,” meaning that it can more accurately match the complex way a human fingertip senses the world.
In previous attempts at haptic devices like this, “once you compare them to real textures, you realize there’s something still missing,” says Sylvia Tan, a PhD student at Northwestern and one of the authors of a new study in Science Advances about the research. “It’s close, but not quite there. Our work is trying to just get that one step closer.”
The wearable, made from flexible, paper-thin latex, is embedded with tiny nodes that push into the skin in a precise way and can move up to 800 times per second. Past devices had low resolution—the touch equivalent of a pixelated image or an early movie from the 1890s with so few frames that the movement looks jerky. Using nodes and arranging them in a particular density improves that resolution.
Earlier devices were also bulky. The ultrathin new technology, which weighs less than a gram, is designed to be comfortable to wear. “A big goal was to make it very lightweight so you aren’t distracted by it,” Tan says. “And [to make] something that we call ‘haptically transparent’—that means that even when you’re wearing it, you can still perceive the real world, so you can perform everyday tasks.”
In the study, users could identify fabrics like corduroy or leather with 81% accuracy. The technology is still in development, but in the future, it could make it possible to feel products as you shop online. It could also have more immediate uses for people who are visually impaired, like making it possible to feel a tactile map or translating text on a screen to braille without a large, expensive device. On devices like microwaves, where physical buttons have often been replaced by flat touchscreens, the wearable could help a visually impaired person know where to push.
It could also help improve human-robot interfaces. “In the medical field, the Da Vinci robot has very good kinesthetic force feedback,” Tan says. “But getting a surgeon to feel exactly what’s happening at your fingertip as you move the angle of your finger is not quite there. And that’s very important for high-skill workers.”