Using Sonar, Smartwatches Now Track Your Fingers In Mid-Air

Tired of Tiny Touchscreens? Smartwatches Can Now Track Your Finger in Mid-Air (+Video)

Jenn U [Engineering.com] | April 15, 2016

First described by Leonardo Da Vinci and best known for its applications in naval warfare, sonar could be coming soon to your wrist. 
FingerIO uses the speakers and microphones already built into smart devices to detect the position and motion of a finger using active sonar. A device with two microphones is required to track motions in two dimensions.  
The technology has been tested with simple inputs such as flicks and scrolling motions, as well as with more complex inputs such as tracing shapes and letters in the air or on a surface near the device.

"FingerIO allows you to interact with mobile devices by writing or gesturing on any nearby surface by turning a smartphone or smartwatch into an active sonar device." Source: http://www.washington.edu/news/2016/03/15/smartwatches-can-now-track-your-finger-in-mid-air-using-sonar/

<more at http://www.engineering.com/DesignerEdge/DesignerEdgeArticles/ArticleID/11890/Tired-of-Tiny-Touchscreens-Smartwatches-Can-Now-Track-Your-Finger-in-Mid-Air.aspx; related articles and links: http://motherboard.vice.com/read/fingerio-uses-sonar-to-extend-touch-controls-to-nearby-surfaces (+Video) (FingerIO Uses Sonar to Extend Touch Controls to Nearby Surfaces. March 20, 2016) and http://www.washington.edu/news/2016/03/15/smartwatches-can-now-track-your-finger-in-mid-air-using-sonar/ (Smartwatches can now track your finger in mid-air using sonar. March 15, 2016)>