This high tech tap uses sensors alright, but it doesn't just turn itself on or off when it senses your hands. The faucet actually moves along the groove as it follows your hand, as you can see in the video.
Why move the tap? Well, the water temperature increases from cold to hot from right to left so moving your hands to just the right spot will get you exactly the temperature you prefer.
The Hidden Tap was designed by Jelmar Moorman. It is not known if it is available yet but the design is part of the Kunst Zonder Kapsones venture company started by Fernando H. Arias. This innovative tap has great potential in hospitals where medical staff have to turn off the tap after washing their hands without touching the actual faucet handles because it has none.