Tarati keyless phone concept

Branko Lukic has designed the Tarati keyless phone concept that is certainly light years ahead of its time, as it comes without a keypad of any kind, instead requiring you to pass your fingers through the keyholes in order to dial. According to Lukic, “the Tarati beckons the user to ‘touch’ someone without physically touching a single key. Its design reflects human connectivity in a less material/mechanical, more sensual, way.” Er, yea, right. That description sounds wrong on so many levels. How do you think the Tarati will be able to detect the presence of a human finger in the holes?