In this project Steve Hoefer uses some electronics to create some fun chattering teeth that will give you some fun incentive to keep brushing your teeth for long enough to maximize effectiveness. A small microswitch waits for you to remove your toothbrush and the 555 timer goes to work counting down your 2 minute brush time. A servo motor that has been hacked to operate in continuous rotation mode is used to move some chompers up and down during the countdown! When the teeth stop chomping you are all done.