The Computational Plasma Science (ComPS) group focuses on using computational modeling to investigate the underlying process that control low temperature plasmas for many practical applications. Low temperature plasmas are nonequilibrium gases which often have electron temperatures on the order of several eV (104 K) and gas temperatures from room temperature to a few thousand Kelvin. These plasmas are often weakly ionized and dominated by collisions. In these conditions, energetic electrons can collide with atoms and molecules to produce excited states, radicals, and other reactive species. In this way plasmas can create reactive chemistry that cannot be accessed in equilibrium thermal conditions.

Areas of Interest

Semiconductor Processing

Low temperature plasmas have been a critical enabling technology for computer chip manufacturing for decades. At every new stage of innovation, new materials, smaller features, and stricter requirements pose new challenges on the plasma tools that are used to create the integrated circuits. Atomic layer etching and atomic layer deposition are becoming increasingly prevalent in the industry, both of which often use plasmas.

Electrification of the Chemical Industry

As renewable energy becomes more abundant, it will become increasingly important to use electricity to replace fossil fuels in the production of various raw materials. For example, nitrogen fixation to produce fertilizer or the generation of methanol. Plasmas can also be used to dissociate CO2 as part of carbon capture and utilization. In some cases, plasmas are combined with more traditional catalysts (e.g. metal nanoparticles) leading to a synergistic relationship.

Biomedical Treatments

Low temperature plasmas have been used for direct treatment of diabetic wounds and have been shown to selectively kill cancer cells. In this case, atmospheric pressure plasmas are generated with gas temperatures very close to room temperature in order to not burn the patient. The reactive species such as OH, O3, and NOx interact with individual cells and trigger an immune response. Electric fields delivered by a plasma may also have a direct impact on cells by increasing membrane permeability. 

Other applications include laser produced plasmas for materials characterization, functionalization of plastic surfaces to change the hydrophilicity, and water treatment to remove persistent pollutants.

In each of these application areas, computational approaches range from simple global (0-dimensional) models to investigate reaction pathways to particle-in-cell methods using high performance computing.