Software developed by Washington University allows users to turn any surface into an input area for their smartphones, by using the phone’s speakers and microphones as a sonar system. The FingerIO system, funded by Google and the US National Science Foundation, works by emitting inaudible soundwaves from the phone’s speakers, and using the inbuilt microphone to detect when the waves are interrupted by the user’s finger. Thus, the system can accurately track finger movements, allowing users to control their devices simply by drawing with their finger on a desk or other nearby surface.
