| AVS 62nd International Symposium & Exhibition | |
| Surface Modification of Materials by Plasmas for Medical Purposes Focus Topic | Thursday Sessions |
| Session SM+AS+BI+PS-ThA |
| Session: | Plasma Processing of Biomaterials and Biological Systems |
| Presenter: | Mark Kushner, University of Michigan |
| Authors: | W. Tian, University of Michigan S.A. Norberg, US Military Academy - West Point A.M. Lietz, University of Michigan N.Yu. Babaeva, Joint Institute for High Temperatures M.J. Kushner, University of Michigan |
| Correspondent: | Click to Email |
Plasma surface modification of materials for biomedical applications typically involves atmospheric pressure plasmas in the form of dielectric barrier discharges (DBDs) or atmospheric pressure plasma jets (APPJs). In many cases, APPJs operate similarly to DBDs with an ionization wave (IW) propagating through a rare-gas dominated gas channel. The intersection of the IW with the surface being treated, for example tissue, in both DBDs and APPJ produces locally large fluxes of ions, UV/VUV photons and electric fields onto the surface. These fluxes are collectively hard fluxes due to the higher levels of activation energy they represent. Remote DBDs and APPJs where the plasma plume does not intersect the surface produce soft fluxes, dominated by neutral reactants. The character and ratios of hard-to-soft fluxes and their compositions are functions of flow dynamics, ambient conditions (e.g., humidity) and pulse power waveforms. In many biomedical applications, the tissue is covered by a liquid (or the intended surface is liquid as in plasma activated water). In these cases, plasma produced activation energy, radicals and ions must penetrate through the plasma-liquid interface, where liquid phase mechanisms then determine the reactants to the tissue. From one perspective, significant advances have been made in modeling these processes and furthering our understanding. From another perspective, there are still significant open questions that models need to address, including the manner of coupling of the gas phase plasma and liquid, gas induced fluid dynamics, long term evolution of the liquid chemistry, reactions at the surface of the tissue and control schemes to minimize variability. A brief overview of progress in modeling plasma modification of biomaterials will be provided followed by examples of the authors’ modeling works for APPJs and DBDs intersecting with model tissues and liquids.