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Preparing basic printing solutions for copper

This part explains how to prepare a basic printing solutions set from raw chemicals to achieve copper printing.


  • 100 ml volumetric flask or graduate cylinder
  • micropipette
  • laboratory analytical scale


The use of graduate beakers and Erlenmeyer flask for volumetric measurements should be avoided.


The following chemical products are required:

  • H2SO4 96% sulfuric acid

  • HCl 0.5 mM hydrochloric acid

  • CuSO4 · 5 H2O copper sulfate pentahydrate

  • H2O deionized water


The purity of deionized water is usually sufficient, but ultrapure water of type 1 ASTM (D1193-91) with a resistivity of 18.2 MΩ·cm at 25 °C is suggested.

In case a 0.5 mM HCl solution is not on hand, it can be prepared by dilution of a 25% concentrated solution:

  • Add 65 µl (73 mg) 25% HCl to 1 lt of deionized water


When handling concentrated acid solution make sure to use suitable personal protective equipment. All chemicals must be used following the handling and storing procedures indicated in the MSDS provided by the supplier.

Waste solutions must be disposed according to local regulations.

Basic chamber solution [Cu] preparation

  • Add ~ 80 ml of 0.5 mM HCl solution in a 100 ml volumetric flask
  • Slowly add 300 µl (0.55 g) of 96% H2SO4 to the flask
  • Fill the flask up to the 100 ml mark with 0.5 mM HCl solution
  • Stir the solution for 5 minutes

This basic chamber solution [Cu] is a 54 mM solution of sulfuric acid and hydrochloric acid (0.5 mM).

Basic iontip ink [Cu] preparation

  • Add ~ 80 ml of basic chamber solution [Cu] in a 100 ml volumetric flask
  • Add 12.5 g of CuSO4 · 5 H2O to the flask
  • Stir the solution until most of the copper is dissolved
  • Fill the flask up to the 100 ml mark with basic chamber solution [Cu]
  • Stir the solution until the copper is completely dissolved

The basic iontip ink [Cu] is a 0.5 M copper sulfate solution in sulfuric acid (51 mM) and hydrochloric acid (0.48 mM). The probe can then be filled with 0.2 to 1 µl of recently filtered ink (200nm pore size filters, filtered less than few days ago).


Preparation steps are not interchangeable and the order of operations must be respected.