A chemical used to make decaffeinated coffee could replace the toxic substances currently used to etch circuits on silicon chips, according to the New Scientist. Supercritical carbon dioxide – formed when it is heated under pressure – is mixed with propylene carbonate, an environmentally benign solvent, so that it can it eat away unwanted parts of the coating used to create the circuitry. The technique, developed by Los Alamos National Laboratory in New Mexico, replaces sulphuric acid or Hydrogen Peroxide that can pollute local water supplies. Until now, the main use of supercritical carbon dioxide has been to extract caffeine from coffee beans.
