Researchers at the Massachusetts Institute of Technology have developed a tiny wireless trackpad that can be worn on a thumbnail.

Called NailO, the prototype trackpad is similar to the stick-on nails sometimes used as a fashion accessory. It attaches to the user’s thumb and can be controlled by running a finger over its surface. ‘NailO is a wearable input device in the form of a commercialized nail art sticker,’ the researchers say. ‘It works as a miniaturized trackpad the size and thickness of a fingernail that can connect to your mobile devices; it also enables wearers to customize the device to fit the wearer’s personal style.’

NailO allows wearers to perform different functions on a phone or PC with different gestures, and the wearer can easily alter its appearance with a nail art design layer, creating a combination of functionality and aesthetics. Cindy Hsin-Liu Kao, an MIT graduate student in media arts and sciences and lead author on the new paper, said the device was inspired by the colorful stickers that some women apply to their nails. ‘It’s a cosmetic product, popular in Asian countries,’ says Kao.

‘When I came here, I was looking for them, but I couldn’t find them, so I’d have my family mail them to me.’ The researchers say a commercial version of their device would have a detachable membrane on its surface, so that users could coordinate surface patterns with their outfits.  ‘It’s very unobtrusive,’ Kao explains. ‘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.’ The researchers say an advantage of the device is that it’s discrete.

Running a finger over a thumbnail is a natural activity, so most people wouldn’t notice this as a deliberate action to control a device. ‘Interactions through NailO can be private and subtle, for example attracting minimal attention when you are in a meeting but need to reply to an urgent text message. ‘Mimicking the form of a cosmetic extension, NailO blends into and decorates one’s body when attached, yet remains removable at the wearer’s discretion, giving the wearer power and control over the level of intimacy of the device to one’s body.’

Researchers are looking to consolidate the components into a single chip, which will make it smaller and reduce power consumption, said Artem Dementyev, a graduate student in media arts and sciences and one of the developers. And they are already talking to manufacturers in China about a battery that could fit in the space of a thumbnail and is only half a millimeter thick. Details of the prototype will be presented at next week’s Computer Human Interaction conference in Seoul, South Korea.