Instructables

About:

Graphite circuits are a fun and potentially useful trick to create paper thin circuits that can power electronics, although they work best for LED’s, due to the low power consumption and inefficiency of the circuit.

Materials needed:

- A piece of paper

- A graphite pencil (not the #2 pencils you used at school when you were a kid, but what “artists” use that’s pure graphite.  If you don’t know what I mean by that use the picture above for a reference.  Also, if you still go to school you may be able to borrow one from your art teacher).

- A battery or electrical source

- An LED or other electronic

- Tape (optional, and it’s to hold down the battery wires or LED to the lines)
- Volt meter (also optional, just so you know if a current is running through the line and how much)

How to Make the Circuit:

This is perhaps one of the easiest projects you may find on intractables to complete.  It’s as simple as drawing the circuit onto a piece of paper, and then connecting the battery and LED to the circuit, and you’re done!  You want to be sure to make the lines plenty thick when creating the circuit though, so that it’s a large path for which to allow electricity to flow through it.  You should pass over the same line five to ten times roughly, dependent on how hard you push on the paper

It’s also best to draw a circle on the side where the battery and LED connect to the paper (fig. 1).  This greatly helps with the flow of electricity, producing a much better current.

Why it Works:

Graphite, although a poor conductor, is still a conductor, thus has the ability to conduct electricity.  Its most common use (that involves electricity) is in resistors, which is why its ability to conduct electricity drops greatly the longer the line is.

P.S.

I’d like to remind you all about being sure to use a pure graphite pencil and to make the lines exceptionally thick.  Failure to do either of these (especially the first one) and the circuit will not work.

ironLes41 year ago
you can also do this with regular pencils like #2 it will still do the same thing!
zorkanator1 year ago
I'm thinking about building a flexible low temp heating disc using graphite for resistance and a heat source and imbedding it in silicone. to make it water proof. Any suggestions?
QSDR2 years ago
are you aware of any long term drawbacks to this method. i was thinking that moisture could wreak havoc, so if it was sealed, would overheating or loss/gain of conductivity of the graphite be an issue. i am currently experimenting making resistors out of electrical tape and graphite pencils, and am unsure of the long term application and its reliability, any light you could shed could save me time on trial and error research?
Hanxonek (author)  QSDR2 years ago
i couldn't imagine any of the things listed being problems, since graphite is already used in many resistors, so i doubt it would overheat or stop working after a short period of time. Good luck with the resistor though, it would be nice to be able to not have to go out and buy one every time I need a resistor. :)
canucksgirl2 years ago
Very interesting. I have a ton of those pencils. You may want to note that a 6B or higher pencil (7B, 8B as you've used, 9B etc) will work quite well. Almost ANY store that sells artists supplies will have a variety of these pencils. :-)