Methods and apparatus for generating atmospheric pressure, low temperature plasma

A plasma generator for generating atmospheric pressure, low temperature plasma, comprising:

• a first electrode that defines a planar bottom surface, the first electrode having a width and length that are each greater than a height extending in a height direction that is perpendicular to the planar bottom surface;
• a second electrode that defines a planar top surface, the second electrode having a width and length that are each greater than a height extending in the height direction that is perpendicular to the planar top surface, the second electrode opposing the first electrode such that the bottom surface of the first electrode faces the top surface of the second electrode;
• a first dielectric layer that is disposed on at least a part of the bottom surface of the first electrode, the first dielectric layer having a relative permittivity between 2 and 15, and a thickness between 1 mm and 3 mm, the first dielectric layer having a first peripheral region;
• a second dielectric layer that is disposed on at least a part of the top surface of the second electrode, the second dielectric layer having a relative permittivity between 2 and 15, and a thickness between 1 mm and 3 mm, the second dielectric layer having a second peripheral region;
• a spacer disposed between the first and second peripheral regions of the first dielectric layer and the second dielectric layer and configured to support the first and second electrodes so as to define a predetermined gap between the first and second dielectric layers, wherein
• the spacer is configured such that the generated plasma extends across a central region between the first and second dielectric layers that is free of spacer material and the spacer is disposed outside the central region, and
• the predetermined gap is between about 1.5 mm and 3.0 mm;
• and
• a power supply configured to supply electrical power to the first and second electrodes at a predetermined voltage and frequency, such that, based on the predetermined gap between the first and second dielectric layers, low temperature plasma is stably generated at atmospheric pressure without arc discharge, wherein the dielectric layers are configured to inhibit arc discharge while maintaining the low-temperature plasma generation.