© VDE, Henning Schacht

Second place, worth 2,000 euros, went to siblings Tara (16) and Connor (14) Albrecht from Lindlar Grammar School. They created a "smart" cat flap that works by means of 24 infrared light barriers and direct control by the chip they designed. This detects whether the cat has something in its mouth when it wants to enter the house. The siblings explain the principle: "If the cat is carrying a mouse, for example, the cat flap is closed."