Nonthermal Biocompatible Plasma (NBP) Sources for Plasma Medicines, Agricultures and Foods

E. H. Choi, G. Park, K. Y. Baik, N. Kaushik, J. S. Choi, I. Han, S. Yi

Plasma Bioscience Research Center & Applied Plasma Medicine Center, Kwangwoon University,
20 Kwangwoon-ro, Nowon-gu, Seoul, Korea 01897

E-mail: ehchoi@kw.ac.kr

Nonthermal biocompatible plasma (NBP) sources and their characteristics operating at atmospheric pressure have been overviewed for plasma medicine, agriculture, and environmental particulate matter. The electron temperatures and plasma densities are characterized to be 0.8 ~ 2.1 eV and 3×1013 ~ 5×1015 cm-3 , respectively, for the NBP soft jet and micro-DBD(dielectric barrier discharge) sources [1]. Here, NBP sources used for the various applications to plasma medicine including rescue vehicle sterilizer, plant growth, agriculture, and environmental particulate matter will be introduced and discussed by soft plasma jet and micro-DBD sources. Also the associated RONS generation mechanism by NBP sources inside the liquid will be discussed by so called synergistic action of plasma initiated UV photolysis [2] and molecular-transport diffusion processes. This mechanism could be well fitted to most of plasma skin treatment as well as to neural differentiation [3] model for degenerate neural diseases.

High voltage nanosecond pulsed arc-plasma devices could be also used to rice, spinach (Spinacia oleracea ) and coriander (Coriander sativum) in both air and N2 environments for inactivation of fungi, enhancement of germination and seeding growth rate along with enhancement of disease resistance and beneficial bacteria. The cylindrical DBD plasma with underwater bubbler could also be used as an environmentally friendly food disinfection device in cleaning processes of the food industry by lipid peroxidation of cell membranes. These NBP sources will also be introduced and their fundamental plasma characteristics will be discussed here for wide understandings.

• [1] J. Sornsakdanuphap et. al., J. Kor. Phys. Soc. 70, 979 (2017)
• [2] P. Attri1et. al., Sci. Rep. 5, 9332 (2015)
• [3] J. Jang, Biomaterials 156, 258 (2018)

Standards of Nonthermal Biocompatible Plasma (NBP) sources and its applications in Plasma Medicine

K.-D. Weltmann, T. Gerling, K. Masur, Th. von Woedtke

Leibniz Institute for Plasma Science and Technology e. V. (INP Greifswald), Germany

E-mail: weltmann@inp-greifswald.de

The plasma technology allows e.g. new therapeutic options in wound healing through effective reduction of a variety of pathogens as well as the stimulation of tissue regeneration but also the degradation of biological and chemical contaminants of surfaces, gases and liquids. For many years, several plasma sources have been approved for the treatment of patients. The sophisticated biomedical applications of plasmas (e.g. in dermatology, dentistry, surgery, cosmetics, etc.) require atmospheric pressure plasma sources, which are now available in many different designs and configurations. [1] Three devices especially for wound healing are certified as medical product class II and also based on clinical trials in Europe. Other devices enter the market, partly without clinical trials and poor physical and biological characterization. There is clearly a need for standard parameters to compare the effectiveness of these sources for different applications. With the help of standards, plasma sources achieve higher acceptance and can be perfectly adapted to dermatological and other medical applications. In addition, such pre-selection criteria ensure the safety of investigators, patients and therapists. A well-known and applicable standard also guarantees the identification of devices that are not suitable as medical plasma sources. [2] In addition, specifications and standards facilitate the introduction of products on the world market.

The contribution will give an overview of plasma sources for therapeutic applications and will discuss needs, perspectives, and approaches for the characterization of plasmas from the basic plasma-physical point of view and selected specific plasma sources used to study various biological effects.

• [1] Th. von Woedtke, S. Reuter, K. Masur, K.-D. Weltmann. Plasmas for medicine. Phys. Rep. 530 (2013a) 291-320
• [2] DIN SPEC 91315:2014-06, General requirements for plasma sources in medicine. DIN Deutsches Institut für Normung e.V., Beuth Verlag Berlin 2014 (in German).

Nanosecond-Pulsed DBD for Medicine and Agriculture

Professor Alexander Fridman

Nyheim Plasma Institute, Drexel University

The tutorial is focused on physics and engineering of nanosecond and microsecond pulsed DBD, as well as different DBD configurations for specific applications in medicine and agriculture. The major topics to be covered are

• Bio-active plasma species generated in DBD
• Engineering aspects of Nano-second pulsed DBD
• Physics and scaling up of pulsed DBD plasma
• DBD plasma uniformity
• Physical & bio mechanisms
• FE-DBD vs DBD jets
• DBD misting devices
• Droplet explosion effect
• Treatment safety parameters
• Medical examples of pulsed DBD application
• Agricultural examplesof pulsed DBD application

Advanced Control of Plasma Devices for Medicine and Agriculture

D.B. Graves

Department of Chemical and Biomolecular Engineering,University of California-Berkeley

E-mail: graves@berkeley.edu

Plasma devices applied for medicine and agriculture have a wide range of different characteristics and properties, matching the wide range of different applications to which they are applied. In all cases, however, they must be properly controlled. In order to design a proper control system, the basic mechanisms of the application must be understood. The first part of the tutorial will review what is known about mechanisms regarding plasma medicine and plasma agriculture.

A common approach is to simply control variables such as applied voltage or power, as well as sometimes gas flow and flowing gas composition in the plasma devices, without regard to the effects of the plasma on its target. A proper control strategy would first define the ultimate goal(s) of the process on the biological system, then work back towards the device and its configuration and characteristics. Process control is a well-established field, since all industrial and other processes must have some degree of control applied to them for both efficacy and safety. Plasmas are no different from other systems in their need for effective control, but they have some interesting characteristics that make them unusual. These include a wide range of time and length scales; strongly non-linear characteristics; and coupling with condensed phases, including liquid, solid and particulate.

In this tutorial presentation, I will briefly review the basic characteristics of plasmas, their applications in biomedicine and bio-agriculture, and the fundamentals of control theory. Several example will be chosen to illustrate challenges and opportunities for advanced control of plasma biomedical devices and processes.

Magnetron sputtering – fundamentals, applications and modeling methods

Dr. Andreas Pflug

The tutorial aims for introducing a basic understanding of the process of magnetron sputtering including its underlying physical mechanisms, applications and methods for numerical modeling. It comprises the following sub topics

• Fundamentals of magnetron sputtering
  • Basic concepts in low-pressure plasma discharges
  • Setup and functionality of a magnetron sputtering source
  • Electron and ion transport in magnetron discharges
  • Sputtering yield and sputtering emission distribution functions
  • Homogeneity issues due to cross corner effect, anode effect, cross magnetron effect
  • Effect of pulsing
  • Ionized magnetron sputtering / HiPIMS
• Reactive magnetron sputtering
  • Explanation of the process hysteresis
  • Voltage characteristics
  • Ion implantation vs. chemisorption of oxygen
  • Concepts for in-situ process control
  • Impact of negative oxygen ions
  • Serial co-sputtering
• Survey on modeling methods
  • Multi-scale approach on modeling methods in thin film deposition
  • Global modeling of reactive sputtering process hysteresis
  • Kinetic modeling of rarefied gas flow and plasma
  • Atomistic modeling of thin film growth

Neutral transport phenomena observed in intermediate pressure plasma discharges

Ho Jun Kim

E-mail: hojunkim@dau.ac.kr

This tutorial introduces a basic understanding of effect of neutral transport on the deposition rate profiles of thin films formed by plasma-enhanced chemical vapor deposition (PECVD). It is explained in detail why variations of the gas velocity and temperature are required in the intermediate pressure capacitively coupled plasma reactor to improve the uniformity of thin films. This tutorial explains also how the modulation of the gas velocity distribution results in a large change in the density distributions of neutral molecules, especially near the electrode edge.

Predictable Modeling for Surface Interactions of Semiconductor and Display Plasma processes

Yeon Ho Im

E-mail: yeonhoim@jbnu.ac.kr

The semiconductor and display plasma processes are getting more difficult due to the limitation of theoretical estimation. Among these processes, the plasma process is emerging as one of the critical bottleneck processes because of its inherent complexity but still depends on the engineering experience. As an effort to address this issue, our group has developed a 3D plasma process simulation tool which was composed of a Zero-D plasma reactor simulator, an effective 3D moving algorithm based on a hash map, a GPU based ballistic transport algorithm, and a surface reaction model. In this work, details of plasma surface interaction such as realistic plasma surface reaction and ballistic transport of neutral and ions are essential to capture the industrial issues. Also, the phenomena are also strongly coupled from atomic scale of surface material to meter scale of bulk plasma. This tutorial will include the introductions of various scientific approaches for predictable modeling of realistic plasma surface interactions. Finally, we will discuss that the predictable modeling of emerging plasma process such as high aspect ratio etching, atomic layer deposition and etching can be achieved from our simulation approach.

Atomic Layer Deposition Fundamentals & Applications

Han-Bo-Ram Lee

Department of Materials Science and Engineering, Incheon National University, Korea

E-mail: hbrlee@inu.ac.kr & http://nanomaterial.kr

Atomic layer deposition (ALD) has received great attention from academia as well as industries because it is a suitable thin film deposition for high volume manufacturing with atomic precision in thickness control and conformality over large area. In ALD, a thin film grows only through surface self-saturation reactions under sequential exposure of precursor and counter reactant in cyclic manner. So, thickness of a thin film is controlled by the total cycle number of ALD and a highly conformal film is formed even in complex 3D nanostructures. In the tutorial, basics of ALD growth and surface reactions will be presented and many applications using ALD will be introduced.