Researchers from MIT Media Lab have created a miniaturized trackpad that fits onto the user's thumbnail and can wirelessly control smartphones, laptops, and wearables. The tiny device — called the NailO — manages to cram a battery, a Bluetooth radio, multiple processors, and a capacitive trackpad into its flexible form factor. Its creators say it could be used for controlling technology when someone's hands are full; to augment traditional interfaces (for example, toggling between letters and emoji while texting); or to give people a way of unobtrusively fielding messages and phone calls in social situations.

In addition to making the NailO easily accessible and relatively discrete, the location of the device means users will never be sore or uncomfortable from wearing it, as there are no nerve endings in the thumbnail. Currently, the NailO has a battery life of just two hours, but its creators, MIT graduate students Cindy Hsin-Liu Kao and Artem Dementyev, say this could be improved with a sleep mode. They found that in tests, a surface press of two to three seconds to wake the NailO was enough to make sure it wasn't activated accidentally.

Kao and Dementyev say that a commercial version of the NailO would not only have better battery life and a slimmer case, but could also be a fashion item, with detachable faceplates letting users customize the device's look. Kao says that the original inspiration for the NailO came from disposable nail art stickers that are popular in parts of Asia. "It’s very unobtrusive,” Kao told MIT News. “When I put this on, it becomes part of my body. I have the power to take it off, so it still gives you control over it. But it allows this very close connection to your body.”