What makes smartwatches so useful—quick access to info through a small device always on your wrist—also makes them challenging for other uses. To overcome the limitations of such a small screen, researchers from Leibniz University Hannover created a special stylus that turns the back of a wearer’s hand into a larger area for doodling.
With the addition of their own cellular connections, smartwatches are very close to replacing almost everything a smartphone can do, potentially allowing you to leave your larger device at home. But even simple tasks, like responding to a text message, are made considerably more complicated with a smartwatch’s minuscule screen. Voice recognition helps, but it’s not always an option, especially when privacy is a concern. Handwriting recognition is better, but scribbling with a single finger, letter-by-letter, is far from ideal.
What the Leibniz University Hannover researchers have developed is a custom stylus for a smartwatch that allows the user to scribble over the back of their hand as an extension of their wearables’ screen. The stylus is roughly the same size as a standard ballpoint pen, with the addition of a bulge near the tip that accommodates a magnet, while a rechargeable battery that’s good for about 12 hours of use fills out the rest of the tube.
The stylus communicates with the smartwatch over Bluetooth (in this case a Huawei Watch 2) but the watch itself is actually crucial for tracking the stylus’ movements and position. The watch features a built-in magnetometer which is normally used to determine what direction the wearer is facing using the Earth’s magnetic poles, but here its functionality is expanded to track the stylus’ motions based on the intensity of the magnetic field detected.
Additional electronics in the stylus keep tabs on the pen’s orientation and angle, while the conductive tip detects when its making contact with the skin as well as taps from a finger facilitating various shortcuts for quickly changing tools, or navigating the smartwatch’s UI while the stylus isn’t being used for drawing. It’s a clever approach because while the stylus could certainly be reprogrammed for drawing in mid-air, limiting it for use on the back of a hand provides physical limitations so a user can better orient where to place the stylus in relation to an on-screen cursor.
For the prototype the research team has focused on doodles as an alternate but expressive way to communicate with others, but there’s no reason the technology couldn’t be expanded and adapted to facilitate hand-writing recognition. Users could write out entire words on the back of their hands, instead of going letter by letter as many modern smartwatches tediously require.