Microwave structures for generating stable arrays of microplasmas.
microwave circuit structures are investigated and shown to support extended arrays of
cold microplasmas. Non-thermal or cold microplasma has been intensively investigated
because the gas temperature remains low, even at atmospheric pressure. This suggests
that atmospheric pressure plasmas may replace arcs and plasma torches in
temperature-sensitive applications including tre... read moreatment of polymers and biomaterials.
This thesis builds on the concept that quarter-wave resonators, in the form of
microstrip transmission lines, can sustain cold microplasmas. While small linear arrays
of such resonators were previously shown to sustain up to 24 microplasmas, the
intrinsically weak coupling between resonators was found to be insufficient for longer,
more uniform arrays. An electrical connection between each resonator (called a coupling
strip) is shown to enhance the coupling among resonators, allowing arrays composed of at
least 72 elements that extend 90 mm in length. In addition to linear microplasma arrays,
circular-shaped microplasmas have also been demonstrated. Theoretical development of an
electromagnetic coupling model known as coupled mode theory shows good agreement with
experimental measurements of microplasma emission intensity as well as electromagnetic
simulations of these devices. Prospects for scaling the microplasma array to greater
lengths are described. These findings may allow for future low-cost plasma processing
using roll-to-roll techniques at pressures of one
Thesis (M.S.)--Tufts University, 2011.
Submitted to the Dept. of Electrical Engineering.
Advisor: Jeffrey Hopwood.
Committee: Alan Hoskinson, and Matthew Panzer.
Keywords: Plasma Physics, and .read less