Modelling of atmospheric pressure plasmas for biomedical applications

Abstract

As interest has increased in the interaction between low-temperature plasmas and living cells or organic materials, the role of modelling and simulation of atmospheric pressure plasmas has become important in understanding the effects of charged particles and radicals in biomedical applications. This review paper introduces the general properties of low-temperature atmospheric pressure plasma devices for biomedical applications and explains recently reported simulation results. Control parameters of atmospheric pressure plasmas, such as gas mixture composition, driving frequency and voltage and the function shape of sinusoidal and pulsed power, are considered through both a review of previous findings and new simulation results in order to improve plasma properties for given purposes. Furthermore, the simulation or modelling techniques are explained along with surface interactions of the plasma for the future development of simulation codes to study the interaction of plasmas with living cells.

Efficacy of Different Carrier Gases for Barrier Discharge Plasma Generation Compared to Chlorhexidine on the Survival of <b><i>Pseudomonas aeruginosa</i></b> Embedded in Biofilm in vitro

“…Especially the electrons of Ar plasma have enough energy to dissociate O-H bonds of water, so the gas humidity may increase the concentration of OH radicals [45]. ROS are essentially downstream products of the plasma due to its reaction with room air or with water on the substrate and result in increased antimicrobial efficacy [45,46]. …”

“…Finally, the high gas humidity of 80% in Ar could have led to a loss of electron density for plasma generation [45] that may have inhibited important antimicrobial components, explaining why the antimicrobial efficacy of Ar + H 2 O plasma was lower than that of Ar plasma. Therefore, a higher energy input for plasma generation or lower Ar humidity may be able to increase the efficacy of Ar + H 2 O plasma.…”

A new hybrid scheme for simulations of highly collisional RF-driven plasmas

“…In general case (see, e.g., [17]) the heavy particle flux is governed by equation which can be obtained by multiplying the Boltzmann's equation by particle velocity and integrating it over velocity space, which yields…”

“…(4) is normally neglected and the ion fluxes are calculated from the right hand side of this equation (drift-diffusion approximation, see the next section). However, it is pointed out in [17] that the right hand side of Eq. (4) vanishes only after the equilibrium drift velocity is achieved and it takes several nanoseconds for a heavy ion to accomplish it.…”

“…The computational domain is assumed to have periodic boundaries. After several nanoseconds the ions acquire the stationary drift velocity (see Figure 6 in [17] and the accompanying discussion in that reference), which can be determined by calculating the total mean velocity of the particle ensemble.…”