While chlorine and ultraviolet light are the standard means of disinfecting water, ozone is equally effective in killing germs. To date, ozone has only been used as an oxidation agent for treating water in large plants. Now, however, a project consortium from Schleswig-Holstein is developing a miniaturized ozone generator for use in smaller applications such as water dispensers or small domestic appliances. The Fraunhofer Institute for Silicon Technology ISIT has provided the sensor chip and electrode substrates for the electrolysis cell.