He s holding the electronic components used in the tiles.
Piezoelectric roof tiles.
When you step on the load bearing glass tile it compresses the piezoelectric element creating an electrical charge that lights up the cavity s 125 leds in the entire footpath about one thousand glass tiles light up in various colors.
The piezoelectric effect is the key the ability of certain materials to generate an electrical charge in response to applied mechanical stress otherwise known as pressure is the key to the success of kinetic tiles.
The piezoelectric process is also reversible so if you apply an electric current to these materials they will actually change shape slightly.
Piezoelectric floors generate many microwatts up to many watts per step depending on space pedestrians frequency and piezoelectric technology.
Branden camp georgia tech.
Electrical power generation using piezoelectric ceramic tile prototype design.