There are many kinds of conductive epoxies, glues, and rubbers available. Unfortunately, they are for the most part quite expensive.
So, for more than four years, I have been trying every possible combination of likely elements, compounds, and solvents that I could get my hands on, in order to make my own truly affordable conductive glue. While I have found several that have excellent low conductivity, they tend to be quite brittle and have a tendency to crack. The conductive glue presented here does not have these problems.
Because this glue is quite flexible and you can vary its resistance, it has potential for different kinds of paint on sensors for robots or other devices. It should be possible to paint on strain gauges on the outside of a regular glove and use it for virtual reality or other control possibilities. Touch sensors and membrane switches can be painted on various flexible or rigid surfaces.
It can be used to paint on wires and resistors and as a glued solder joint. It can also be used to paint on strain gauges, temperature sensors, electromagnetic shielding, antennas, and push-button switches. I suspect, that with more experimentation, it may be possible to use it to create capacitors, diodes and transistors.
Step 1: Materials for the Conductive Glue and Circuit
Carbon Graphite, fine powder-Available in larger quantities at http://www.elementalscientific.net/
Available in smaller quantities at your local hardware store. It's called lubricating graphite and comes in small tubes or bottles. The brand I used successfully is called AGS Extra Fine Graphite, but no doubt there are other brands that will also work.
Performix(tm) liquid tape, black-Available at Wal-Mart or http://www.buytape.com
Mixing cups or glass container
1/4 and 1/2 teaspoon measuring spoons
Glass or plastic mixing rod
Cardboard for stencil
Toluol paint thinner (optional)-Available at most hardware stores.
Conductive thread (optional)-Available in larger spools at http://members.shaw.ca/ubik/thread/order.html It is available in smaller spools at
Circuit materials of your choice