Belgium-based artist Dries Depoorter created this clever art installation titled Recharge. It features "a chair where you can relax and charge your phone. However, your phone will only charge when your eyes are closed."
While you're seated, a camera captures video of your face that's analyzed in real time by a Raspberry Pi to determine if your eyes are indeed shut. If they are, the mobile charger by the chair is activated.
Below, images of the Recharge installation and video of the software being tested.