Making a conductive copper ink pigment

I got it into my head that I’d like to DIY a circuit-writing pen. This is Part 1 of the project, the first run at making a copper pigment. This is a process for precipitating copper nanoparticles. I know there are other methods, with longer-lasting materials, but they require more equipment and precision. I thought I’d start with easy and document the improvements. This is a really easy chemistry experiment suitable (IMO) for classrooms, garage chemists and hobbyists.


  • copper sulfate II pentahydrate (CuSO4·5H2O)
  • ascorbic acid (C6H8O6)
  • water


  • beakers x2
  • mixing spoon
  • water kettle

CuSO4*5H2O + C6H8O6 = Cu+ + H2SO4 + C6H6O6 + H2O copper sulfate + ascorbic acid = copper + sulfuric acid + dehydroascorbic acid + water