EXPERIMENT 8

Making a “Fuel Cell” *

THINGS YOU NEED: A nonmetallic mesh tube, such as a woman’s plastic hair roller, measuring about 3" long by 1" in diameter (see drawing). Three small rubber bands or some string. Thin sheet of zinc or galvanized steel 3½" by 2". A large gauze pad (see text). A tablespoon or so of natural powdered graphite (one tube of powdered graphite lubricant should do the trick). Flour. Salt. A saucer. Galvanometer from Experiment 2.

     Making a fuel cell would be easy if we had the right mate- rials. Trouble is, the right materials are either dangerous or difficult to get in small quantities. So let’s take an easier path. Let’s build a device that is considered to be a form of fuel cell. It uses zinc as the fuel (one electrode), air as the oxidant (the other electrode), and salt water as the electro- lyte.

     First pour all the graphite into a small mixing container. Next, in a separate container, prepare a binder of 1 part flour and 4 parts water. Then add the binder to the graphite, a little at a time, and stir. What we want to do is end up with a thick paste, like peanut butter.

     Now from the gauze pad cut two strips as wide as the mesh tube (hair roller) and about 7" long. If you don’t have gauze, try a paper towel; fold it in four layers and cut it to size.

* The device in this experiment was designed by research scientist Hiry West of the McGraw-Edison Co., Bloomfield, N.J.