Get Your Science On: Human Powered Clock

 In Get Your Science On, Shopcasts and Videos

This week John shows us how to build a human powered clock.

What’s Going On

Technically it’s the two different types of metal that are powering the clock. The copper and the zinc coating in the galvanized steel both have different electron affinities, and a voltage difference is set up between the two metals. You and a friend act as a conductive path for electricity to flow, so each of you is an essential part of a separate battery!


2 pieces galvanized
2 pieces of copper
electrical wire
a clock that runs on a single battery
solder or conductive tape to connect wires (optional)


How to Build

Use a wire to connect the copper to the positive battery terminal of the clock. Use another wire to connect the galvanized steel to the negative terminal of the clock. Use a 3rd wire to connect the remaining pieces of copper and galvanized steel together.

To use, each person should hold one piece of copper in one hand and one piece of galvanized steel in the other. Make sure you are only holding one piece of metal the is connected to the battery so you make one giant circuit!