The Flock Clock uses male and female drinking birds to display time. Binary addition of the female birds (left to right) yields the hour. Binary addition of the male birds (multiplied by five) yields the minute--within five minutes. An Arduino processor provides the signals needed to drive Peltier cells which heat the fluid in the birds and causes the bobbing motion.
102-1671-nd Peltier digikey.com
pb1124-nd relay digikey.com
drinking birds teachersource.com
320081 5 volt 6 amp power supply for Peltier jameco.com