Sterilisation with low-pressure microwave plasmas

The aim of this article was to show that low-pressure microwave plasmas are suitable for the sterilisation of materials for all kinds of applications. Therefore, several microwave plasma sources were used to treat test substrates with a defined initial contamination of 106 test spores. Spore reduction kinetics are presented for four different test spores obtained with different plasma sources and different working gases. A fast spore reduction of four orders of magnitude after less than 1 s of plasma treatment could be achieved. Furthermore, the results prove that the main mechanism responsible for this fast inactivation is the effect of UV and VUV light that is produced in the plasma.