Unconventional Switch, The Backpack Alarm

For our switch we used the zipper of a backpack. The idea of the device would be an anti-theft device. When 2 zippers on the backpack are connected the device would remain off. However, if the backpack were to be opened the 2 zippers would break the circuit sounding the alarm or lighting a light to alert the owner of the backpack that someone has unzipped it. When the zippers are closed the 2 zippers would barely touch so all it would take to alert the owner of the backpack is a slight unzipping of the backpack. You could also design a switch to the arm and disarm the device so that the real owner of the device would now sound their own alarm.