Our devices continue to shrink smaller and smaller while our fingers remain the same size. One group of researchers has found a way around this issue by developing technology that turns your arm into an interface for your smart watch, Mashable reports.

SkinTrack is a wearable interface that allows users to control a device by moving a single finger across their skin. To use it, wearers slip on a high-tech ring that connects to a smart watch band around their wrist. The band calculates the exact position of the ring and its distance from the wrist with up to 99 percent accuracy, making it possible for users to launch apps, play music, and make phone calls without ever touching the screen.

The idea of transforming a user's arm into a virtual keyboard has been explored in the past. In this demo from the Japanese tech company NEC, augmented reality glasses are used to make an animated keyboard appear across the wearer's forearm. But no matter how cool the effect looks, consumers have yet to warm up to the idea of wearing a pair of cyborg glasses on their face.

A low-profile ring might be easier to market, but it could be a while before you see the feature in commercial products. To test out their device, researchers at Carnegie Mellon's Future Interface group had to build a custom-made watch prototype from scratch. You can see their demonstration in the video above.

[h/t Mashable]

All images courtesy of YouTube.