Conductive Paint Lessons

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Lessons on Conductive Paint

Related to Pulse Choker Hack Notes for July 15th, 2009:

"We tried silk screening silver conductive paint (MG Chemicals 842-20G) onto two different types of fabric, a water resistant one and a water proof "leather like" one. Both showed very high resistance (higher than the meter can read) even for very short thick traces. It looks really cool though - hopefully we can figure out what we're doing wrong, and make this work. We also tried measuring the resistance of a huge dollop of paint on the spoon: silver = infinite resistance (!), copper = 200kOhms. It didn't matter if the paint was dried or wet. Note that we shook the bottle prior to use to ensure that the silver particles were dispersed evenly."

Types of Conductive Paint

    • Copper (Cu):
      • Higher resistance - ~5 ohms per square. We bought CuPro-Cote #292-4 from Less EMF Inc.. The paint wasn't viscous, not even quite as viscous as tempera paint.
      • Reasonably priced - ~$30 for 4 oz
  • Transparent paint
    • Orgacon from Agfa - conductive, can be flexed, transparent, can be silk-screened


  • Alternatives
    • Wire glue - $4 for 0.3 oz
    • Conductive pen

Heeds

  • Shake paint well to ensure metal particles are well dispersed
  • Keep ink wet while working with it. If work time is protracted, mix paint frequently
  • Resistivity measures are suppose to be accurate only when paint has fully dried
  • Some paints are more dilute than others. One guy used silver paint, which bled beyond his mask (accelenation.com).


Uses

  • Auto repair
    • It may be cheaper to purchase conductive paint as the rear window defogger paint at the auto store. I haven't done so. Most defoggers use copper paint.
  • Microscopy, i.e. scanning electron microscopy (SEM)
    • Companies specializing in SEM equipment note that some paints particularly plantinum may need to be placed in an ultrasonic bath for a few minutes (SPI Supplies)
    • Microscopy often utilizes different concentrations of metal particles in conductive paint, so these websites can provide you with a gradient of resistivity in their inventory of paints. M.E. Taylor's SEMicro division has three concentrations of silver paint: 18%, 36%, and 50% Ag.
  • Art
    • Paper Circuits by Leah Buckley: conductive paint, magnetic paint, magnets
    • Paper printed circuit board by Peter Blasser