Copper Foil

• copper foil
• alligator clip sensor
• scissors

You can find copper foil at a surplus stores, art supply stores--or gardening stores (copper foil tape is used to keep snails away).

Copper foil comes in different forms - on rolls, little pieces, and even as rolls of adhesive copper tape.

You can cut it to any size or shape; it folds; and is easy to glue or tape to your project.

The copper can have sharp edges, so handle it carefully so that you don't get cut.

Pieces of copper work well with alligator clip sensors. Copper is a good conductor of electricity -- and it can extend the little tip of the alligator clip.

You can attach copper foil to places you wouldn't have room to attach a clip.

If you use alligator clips, just clip them on to the copper foil.

(If you don't have alligator clips, you can just attach a piece of wire to the foil.)

Copper foil is great for sensing a metal ball. (It's easier to trigger than a switch or touch sensor.)

In the photo, two pieces of copper are placed about 1/4-inch apart. Then, the alligator clip sensor is attached to the copper. When the metal marble rolls along the copper, it completes the circuit (and trips the sensor).

Here I used a piece of copper to make a little plastic figure into a sensor.

I folded the copper down the back of his legs and under his feet, taped it on, then used a alligator clip to grab the end of the copper.