According to the California Energy Commission, you can make a voltaic battery out of fruits and vegetables such as lemons or potatoes. Any fruit or vegetable with a moderate to high acidity level can use a chemical reaction to conduct electricity. A lemon, with higher acidity than other fruits and vegetables, will create the strongest battery.
Straighten a 2-inch copper wire with your fingertips. Soften the lemon by squeezing carefully without breaking the skin.
Push the copper wire firmly through the skin and into the lemon to create a copper electrode.
Straighten the 2-inch steel wire with your fingertips.
Push the steel wire through the skin and into the lemon as close to the copper electrode as you can without allowing them to touch.
Wet your fingertip with saliva or water and touch the tips of both electrodes at the same time. You will feel a mild electrical current as you close the circuit with your finger.
When you have finished the experiment, carefully remove the electrodes one at a time without allowing them to touch each other.
You can use the tip of your tongue to close the circuit as well. After the experiment, you can still eat the lemon.
The amperage produced from a lemon is very low, but you should still use caution when experimenting with electricity and chemical reactions.