About Potato Clocks

It may seem a bit cliched--especially with the multitude of movies that depict the device as a staple of any science fair--but the potato clock is actually a working mechanism that almost anyone can easily construct. You only need the tools and instructions to make it happen.

Significance

Though predominately seen as food, the potato is also considered an "electrochemical cell"--an object that generates an electromotive force, otherwise understood as voltage, from a basic chemical reaction. When a nail is pushed into a potato and linked to a copper wire that has been fixed into the same potato, the zinc on the nail will actually transfer electrons between the nail and the copper wire, generating a current. This current, while not strong enough to really feel in your body, will generate enough electricity to power a clock.

Features

Though there are a number of kits available on the market, you can usually fashion a potato clock from a number of objects you have lying around the house. All you'll need is a single potato, a copper wire, nails (galvanized), alligator clips and a clock--preferably of the low-voltage variety (around 1.5 to 2 volts).

Function

To fashion the potato clock, cut the potato in half and insert a nail into each portion. Cut two sections of copper wire from your roll. Insert one end of the copper wire into the potato. Repeat the same procedure on the other portion of the potato with your second piece of copper wire. Connect the copper wire of the first portion of the potato to the positive station of the clock (where you'd situate the positive side of the battery) with an alligator clip. Connect the nail of the second portion of the potato to the negative station of the clock (this time, where you'd situate the negative side of the battery) with another alligator clip. Connect the nail in the first portion of the potato to the copper wire of the second portion. You should now be powering the clock.

Considerations

If you can't find a copper wire stashed away in one of your household drawers, you can actually use a penny as a substitute. Simply push a separate penny into each portion of the potato where you would normally fix the wire, then hook up the clock as already described. You don't even need to set foot in a store--unless, of course, you need to pick up a low-voltage clock because you don't have one available at home.

Potential

You can use the same standard construction to make a clock from other fruits, vegetables and even drinks. You should be able to power the same clock with a couple of lemons, bananas, apples or avocados, as well as pickles and some soft drinks (mostly of the sugared variety).