Low-temperature atmospheric pressure plasma devices for biological applications

Atmospheric-pressure plasma systems are a fast-emerging field of engineering research as they obviate the requirement of the costly and bulky vacuum systems required by low pressure plasmas. A wide range of applications such as medical treatments, surface sterilisation and aerodynamic flow control have recently been emerging in the literature, presenting exciting opportunities for new plasma devices or treatment methods to be brought to the forefront. These plasmas offer an alternative to existing applications such as cleaning or chemical production as they hold the advantage that they do not require any other chemicals such as bleach, the only input to the system being power and air. Plasmas can be utilised in so many applications because of the clever design of the devices that create them, most applications require a new design configuration in order to optimise the plasma for each case. As with many fields, developments are required in the efficiency, cost, efficacy and size of said plasma devices. Experimental results prove that the plasma devices developed have advanced the efficacy of atmospheric-pressure plasma devices by increasing the flux of reactive species from the plasma to the sample. Testing of the developed plasma devices was carried out using optical emission spectroscopy, optical absorption spectroscopy, schlieren imaging and degradation of potassium indigo trisulphonate. Focus in the area of sterilisation using plasmas has triggered many plasma devices to be developed worldwide, each one being tested for efficacy by its home institution. Prior to this work efficacies had to be drawn from many different testing methodologies so direct comparison between plasma devices was problematic. This work proposes a reference protocol of Bacillus subtilis spores filtered onto polycarbonate membranes for the preparation of biological samples to carry out direct comparison of plasma devices for biological inactivation. Atmospheric-pressure plasma systems are a fast-emerging field of engineering research as they obviate the requirement of the costly and bulky vacuum systems required by low pressure plasmas. A wide range of applications such as medical treatments, surface sterilisation and aerodynamic flow control have recently been emerging in the literature, presenting exciting opportunities for new plasma devices or treatment methods to be brought to the forefront. These plasmas offer an alternative to existing applications such as cleaning or chemical production as they hold the advantage that they do not require any other chemicals such as bleach, the only input to the system being power and air. Plasmas can be utilised in so many applications because of the clever design of the devices that create them, most applications require a new design configuration in order to optimise the plasma for each case. As with many fields, developments are required in the efficiency, cost, efficacy and size of said plasma devices. Experimental results prove that the plasma devices developed have advanced the efficacy of atmospheric-pressure plasma devices by increasing the flux of reactive species from the plasma to the sample. Testing of the developed plasma devices was carried out using optical emission spectroscopy, optical absorption spectroscopy, schlieren imaging and degradation of potassium indigo trisulphonate. Focus in the area of sterilisation using plasmas has triggered many plasma devices to be developed worldwide, each one being tested for efficacy by its home institution. Prior to this work efficacies had to be drawn from many different testing methodologies so direct comparison between plasma devices was problematic. This work proposes a reference protocol of Bacillus subtilis spores filtered onto polycarbonate membranes for the preparation of biological samples to carry out direct comparison of plasma devices for biological inactivation.