Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 1 Masaryk University Brno Department of Physical Electronics Atmospheric Pressure Plasmas – Basics and Applications Ronny Brandenburg Atmospheric pressure plasmas Lecture I: Introduction, overview on sources and selected applications • Incidences, Electrical breakdown • Types and classification of atmospheric pressure plasmas • Selected applications Lecture II: Diagnostics of non-thermal atmospheric pressure plasmas • Electrical characterization • Optical emission spectroscopy, fast optical/spectroscopic methods • Surface charge measurements Lecture III: Environmental aspects of plasma science • Plasma chemistry • Depollution of gases • Treatment of liquids Lecture IV: Plasma life-science applications • Biological decontamination • Plasma medicine Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 2 Atmospheric pressure plasmas I Introduction, overview and selected applications 1. Introduction - Incidences and relevance 2. Basics - Electrical breakdown - Thermal and non-thermal plasmas - Scaling laws and miniaturisation - Classification 3. Arc discharges and plasma torches 4. Barrier discharges 5. Corona discharges 6. Plasma jets 7. Microplasmas 8. Summary Atmospheric plasmas 1. Introduction: From lightnings to microplasmas Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 3 “Atmospheric Plasmas” Pressure range log10 pressure 10-10 Pa 10-7 Pa 10-1 Pa 3 103 Pa3 103 Pa 1.013 105 Pa 10-12 mbar 10-9 mbar 10-3 mbar 30 mbar 1013.25 mbar Extremely High Vacuum Atmospheric Pres. (AP) Low Vacuum Medium Vacuum High Vacuum High Pressure Plasmas in standard air Plasmas in open atmosphere Plasmas at elevated press. Lightnings 1) cloud-to-ground lightning CG 2) intracloud lightning CC 3) cloud-to-air lightning CA M.A. Uman “All about lightning” Dover Publications, New York speed up to of 60,000 m/s temperature up to 30,000 °C current 5 – 20 kA (up to 200 kA) electric field: 3-4 kV/cm total pow er: sev. hundred MW Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 4 „Megalightnings“ (upper atmosphere) T. Neubert, Science, Vol 300, 2 (2003) http://www.eur osprite.net; www.spritesandjets.com transient luminous events (TLE) 9 APP in laboratory and industry Electromagnetic radiation microwave excited plasmas (915 MHz, 2.54 GHz) ignition structure needed usually “hot” plasmas Electron beam electron accelerating tubes (beam gun, keV ... MeV) extensive installations used for flue gas treatment (depollution) Electrical gas discharge high voltage power supply DC, AC, pulsed // frequency: Hz ... MHz electrical breakdown according to Paschen law (breakdown voltage depend on pressure x distance) Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 5 Incidences of atmospheric plasmas Nature St‘ Elmos Fire Aurora Ligthnings Transient luminous events Engineering and Technology Partial discharges (electrical engineering) Switching Welding Melting and incineration Surface activation Chemical conversion Ligth emission Environmental technology Research and Development Plasma medicine Film deposition … High economic impact! Detection/Protection Process optimization Novel Applications Special features / relevance High density of neutral background gas = high collision rates rapid breakdown high and rapid mass/energy transfer (heating, chemistry, …) high space charges (causing e.g. instabilities) higher breakdown fields Avoidance of vacuum devices (pumps, chambers, ...) less cost and maintenance intensive linear throughput processing Several applications require ambient/open conditions biomedical applications (“Plasma medicine”) decontamination of exhaust and flue gases material processing plasma chemistry (3-body collisions) ... but be aware of: gas consumption; by-products; high voltage, heating, etc. ... Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 6 Microdischarges and microplasmas = Discharges with dimensions of µm ... mm Microplasmas Generated in small structures or narrow cavities (e.g. as arrays or in tubes) characteristics differ from traditional plasmas at low er pressures Microdischarges (Filamentary plasmas) Formation of fine plasma channels, so-called filamentary discharges Portability and non-equilibrium („cold“) character offer variety of new applications J. G. Eden et al., Univ ersity of Illinois gap 1 mm 20 mm50 µm2 Atmospheric plasmas and microplasmas 2. Physics of plasmas at atmospheric pressure Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 7 Electron avalanches H. Raether „Electron av alanches and breakdown in gases“ (1964) Yu.P. Raizer „Gas Discharge Phy sics, Springer-Verlag, Berlin Heidelberg (1991) Ionisation cascade Tow nsend-avalanches John S. Townsend (1868-1957) z e eN α 1= eDi v ,αν = α 1. Townsend coefficient iν ionisation frequency eDv , drift velocity of electrons ionisation electron drift e- z Shape/charge distribution of el. avalanches Cloud chamber track of a single avalanche by H. A. Raether (1909-1986), 1939 H. Raether „Electron av alanches and breakdown in gases“ (1964) Yu.P. Raizer „Gas Discharge Phy sics, Springer-Verlag, Berlin Heidelberg (1991) cathode anode N2 200 mbar d=1.7cm z ie µµ >>electron/ion mobility: Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 8 Avalanche breakdown H. Raether „Electron av alanches and breakdown in gases“ (1964) Series of avalanches lead to breakdown Avalance-to-streamer transition @ high electric fields and long gaps Townsend breakdown + -Townsend-Criterion: self-sustained discharge Direct ionisation ( ) 11 =−⋅ d eα γ Secondary electron emission by ion impact z ee eNN α 0,= eDi v ,αν = α 1. Townsend coefficient iν ionisation frequency eDv , drift velocity of electrons γ 3. Townsend coefficient γ α (cosmic) radiati on secondar y emission 2nd avalanche E0 1st avalanche cmbarpd ⋅<1 Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 9 Streamer breakdown + - E0 ---- + + + + ---- ---- + + + + + + + + Er = E0 Er Er Raether-Meek-Criterion 8 10≈d eα cmbarpd ⋅>10 concept developed by L.B. Loeb; H. Raether; J.M. Meek significant field distortion due to space-charge buildup in a single avalanche formation of thin ionised channel(s) 18 0 ≈=∫ Kdxx d α Photoeff ect starting secondary av al. primary av al. ie µµ >> ie µµ , Electron and ion mobility + - + Streamer family Yu.P. Raizer „Gas Discharge Phy sics, Springer-Verlag, Berlin Heidelberg (1991) Positive or cathode- directed streamer (most common) propagating distortion of electric field due to spacecharge accumulation secondary avalanches in front of positive streamer end v Negative or anode-directed streamer @ large gaps & overvoltages secondary avalanches in front of negative streamer head (a) photons and (b) electric field second. avalanches v Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 10 Streak photo at pre-spark stadium K.H. Wagner; Zeitschrif t f ur Phy sik 204 (1967) 177 / Loeb & Craggs; Wiley 1978 z-position time cathode anode N2 500 mbar 3cm streamer velocities up to 106 m/s (= 10 times vD,e) Partial breadkown - leader, spark, arc Streamer Leader Spark (Lightning) Arc P(I) Leader Streamer ++ + + ARC PartialBreakdownArcingBreakdown Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 11 Partial breadkown and spark Spark Streamers Influenzmaschine; Uni Greifswald APP tend to LTE-plasma regime! Local Thermal Equilibrium (“thermal”) microreversibility of elementary processes and equipartition of energy between all species of particles “local”: long-range effects like radiation not in in thermodynamic equilibrium (Planck’s law not valid) J.R. Roth „Industrial Plasma Engineering”, Vol. 1: Principles, IOP Publishing Ltd 1995 Ti ≈ Tg ≈ Te Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 12 Non-LTE-plasmas at atmospheric pressure APP are not solely LTE plasmas Kekez et al. 1970 Mechanismn of glow-to-art transition: Increase of current density j increase of local electric field constriction of ionization channel (filamentation) = increase of j cathode spot formation and thermal ionization thermalization Limitation of discharge duration (transient) • Certain number of collisions necessary to establish equil. Limitation of current / power density • reduction local dissipated energy density/ electric field Non-thermal plasma: Te > Ti > Tg Invariants and scaling .2 const p j = )( dpfUBreakdown ⋅= .const N =α N E Paschen law J.W. Hittdorf Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 13 Invariants and scaling .2 const p j = )( dpfUBreakdown ⋅= .const N =α N E Paschen law Pseudo-spark minimum )( dp⋅ BreakdownU Potential Pressure Scaling p increase d decrease = Miniaturisation Limitations: 3-body collissions at higher pressures High aspect ratios (importance of wall effects like field emission) Plasma chemistry Instabilities (e.g. glow to arc transition) p increase j constant r decrease = Constriction .2 const p j = )( dpfUBreakdown ⋅= Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 14 Thermal Plasmas “Cold” Non-Thermal Plasmas Translational (“Hot NT”) Plasmas Ti ≈ Tg ≈ 300 ... 400 K Ti << Te < 105 K (10 eV) Ti ≈ Tg ≈ Te Tx < 5 103 ... 104 K Ti << Te ≤ 104 ... 105 K Ti ≈ Tg ≤ 4 103 K Barrier discharges Plasma TorchMicroplasma-Arrays Thermal Plasmas ArcGliding Arc Arc jet Classification Plasma jets Coronas 1 3 2 4 5 6 7 8 1 2 3 4 5 6 7 8 Microwave Driven Plasmas Non-Thermal (NT) Plasmas Atmospheric pressure plasmas 3. Arc discharges, arc jets, and plasma torches Photo: Achim Grochowski Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 15 Arcs at 1 atm: LTE-plasmas! Typical cathode emission: field emission and thermionic emission Electron density: 1022 < ne < 1025 m-3 Ionization degree: SAHA equation Arc current: 50 < I < 104 A; Voltage: some 10 V; Electric field: 500 < E < 5000 V/m LTE: 0.5 eV Eig(pg) - - - - - - - - - - - - - Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 24 Filamentary plasmas T/4 Filamentary structures MD footprints (Lichtenberg figures) Regular MD-pattern U. Kogelschatz ABB Switzerland; Purwins et al., Uni Münster Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 25 Microdischarge properties duration: 1-10 ns radius: 0.1 mm transported charge: 100-1000 pC current density: 100-1000 A cm-2 concentration of electrons: 1014 bis 1015 cm-3 averaged energy of electrons: 1-10 eV gas temperature: near room (cold) - + - - + + Diffuse vs. filamentary BDs Filamentary Diffuse statistical MDs, ns-range periodical (appl. frequency) µs-range I Uappl MD-pulses t U I t U Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 26 Diffuse BDs (APGD; APTD) Atmospheric pressure glow discharge He, Ne, Ar/NH3; j max ≈ 1 mA/cm2 Z. Navratil et al.; Plasma Sources Sci. Technol., 15 (2006), 8-17 Atmospheric pressure Townsend discharge N2; jma x ≈ 0.1 mA/cm2 R. Brandenburg et al., J. Phys. D: Appl. Phys., 38, 13 (2005), 2187-2197 Preventing filamentation by gas mixture: minimum initial electron density and ionization rate before breakdown pre-ionisation by x-rays or second discharge supression of rapid ionization during breakdown minimum dU/dt minimum δ(α/N)/δ(E/N) (best in case of helium!) indirect ionisation processes (e.g. Penning-ionisation) slow-down of ionization/breakdown by geometry/materials residual density of ions and excited species (e.g.metastable states) surface properties: γ, ε, σ, humidity, ... by power control Short pulsed plasmas (ns-range) Matching of external circuit parameters Resistive barrier material U. Kogelschatz IEEE Trans. Plasma Sci. (2002) Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 27 Plasma- CHEMISTRY Electric Field Breakdown Electrons & Ions Excited Species Chemical Reactions Discharge- PHYSICS Time 10-12 s ... BOLTZMANN-equation cross-sections of elementary processes 10-9 s ... POISSON-equation; equation of continuity kinetic coefficients 10-6 s ... 10-3 s diffusion; heat transport local densities, temperatures, ... surface treatment modification coating erosion ozone generation pollution control hydrogenation of CO2 NOx reforming radiation sources excimer lamps AC plasma displays SD CO2-laser General principle and major applications Ozone synthesis 1. Dissociation of O2 e + O2 → O- + O → O + O + e → O + O* + e e + N2 → N2* + e N2* + O2 → N2 + 2O 2. Formation of O3 O + O2 + M → O3 + M (M= N2,O2) Ozone yield (g/kWh) Oxygen Air Sinusoidal v oltage 150 ... 180 80 ... 95 Impulse v oltage (kV/ns) 240 ... 290 130 ... 140 Theoretical limit 430 ... 450 200 ... 220 O3: important oxidant water cleaning (advanced oxidation) paper bleaching ozone can’t be stored “on-site” production high pressure but low temperature required Largest facility in Brazil: 500 kg/h Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 28 Modern Ozonizers Wedeco Ozonia U. Kogelschatz et. al; Journal de Physique 7 (1997) C4-47 annular discharge gap Surface „Corona“ treatment Activation to change surface energy / wettability or Coating printing glueing Activation: electrons cause chain breakage incorporation of polar groups and other functional groups Coating (Aldyne): admixture of precursors (ppm of silane) f igures: tigres GmbH; sof tal GmbH on polymers, textiles, ... Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 29 Corona stations U. Kogelschatz, J. Salge in „Low Temperature Pl asma Physics“ Wiley-VCH Berlin (2001) Tantec Softal one side two side web speed: 10 – 200 m/min residence time: a few seconds energy deposition: 0.1 – 1.0 J/cm2 Aldyne process L’Air Liquide/Softal Silane-Precursor: reactiv e molecular lay er which f orm stable chemical bonds with commercial inks (v arnishes water-based, solv ent-based or UV-curable) Applications: Labels; Flexible packaging (f ood and non f ood); Tapes markets, Graphic arts (Primer f ree UV Offset Printing and gluing of CPP packaging); Flooring / Cov erings Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 30 Excimer lamps UV curing in web and sheet offset press UV printing Photolytic structured metal deposition Room temperature oxidation of silicon Plasma displays Panasonic (2008): Largest Plasmadisplay 3.81 m (150 Zoll) diagonal/ 8.84 Megapixel Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 31 Atmospheric pressure plasmas 5. Corona Discharges http://www.dpchallenge.com/ Principle / geometry Point Electrode Plate AC or DC Point-to-plane or wire - non-uniform electric field glow drift region region Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 32 Corona discharge Wire-in-cylinder Coaxial electrode Multi-wire-plate arrangement Corona onset – Peek‘ law δδδδ = N / N0 R = Wire Radius J.J. Lowke and F. D‘Alessandro J. Phy s. D: Appl. Phys. 36 (2003) 2673-2682 8 10=M Streamer-Breakdown Townsend-Breakdown 4 103⋅≈M ( )( ) 4 10exp =−= ∫ dxM ηα Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 33 Modes of corona discharges Chang et al. IEEE Trans. Plas ma Sci. 19(1991) Electrostatic precipitators Voltage: 30–80 kV Dow n to 1 µm diameter Up to 300.000 Nm3/h M. Bank „Basiswissen U mwelttechni k“ 2006 ABB Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 34 Atmospheric pressure plasmas 6. Plasma jets Diversity in design, operation ... Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 35 Plasma pencil (1997) M. Klíma, J. Janča, V. Kapička, P. Slavíček, A. Brablec and others APPJ - Atmospheric pressure plasma jet A. Schuetze et al., IEEE Trans. Plas. Technol. 26 (1998) Helium: >> low breakdown voltage >> high heat conductivity Selwyn et al; Los Alamos National Laboratory Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 36 Plasma jet principle “Gas flow transports plasma outside electrode configuration” non-thermal plasmas pulsed dc ... GHz Power 1 ... 1 kW Gas High v oltage Nozzle or tube Electrodes Substrate Plasma “Remote-type” active plasma between electrodes plasma jet = effluent or afterglow (long lived species) potential free “Active-type” active plasma between electrodes and between nozzle and substrate plasma jet contains free electrons current transport through substrate Plasma jet configurations a) using 1 powered and 1 grounded ring electrode b) without grounded ring electrode c) combination of 2 tubes whereas the inner tube is streamed with a noble gas f or discharge ignition and the outer tube with a precursor d) composed of two coaxial electrodes with a dielectric in between e) consisting of an inner RF driv en needle electrode and a grounded ring electrode f ) without grounded ring electrode Ehlbeck, Pollack, Winter, et al,. J Phys D 2011 Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 37 Turbulent „active plasma“ jet P= 1 W; Q= 1 slm P= 10 W, 10 slm P= 4 W; Q= 1 slm P= 20 W; Q= 1 slm Active, filamentary plasma cooling and expansion by argon- gasflow jet operates in it’s “own” atmosphere Argon Nozzle Filaments RF Needle electrode Plasma bullets (noble gases) J. Shi et al; Phys. Plasmas 15, 013504 2008 hypersonic train of plasma bullets travelling ionisation fronts Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 38 compact and modular low power consumption penetrates in small structures non-thermal plasma R. Foest et al., Plasma Phys. Control. Fusion 47 (2005) B525-B536 P = 5 … 40 W f = 13 MHz / 27 MHz gas: Argon, N2, …. Q = 1 … 20 slm kINPen Treatment of complex workpieces kiNPen Plasma jet Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 39 Plasma-Jet Ring electrode (grounded) Inner electrode (RF) Capillary (quartz) Process gas Carrier gas + precursor Configuration with precursor admixture Self organized plasma jet J. Schäfer, Eur. Phys. J. D 60, 531–538 (2010); J. Phys. D: Appl. Phys. 41 (2008) 194010 „Locked mode“ quasi-laminar flow: controlled number of equidistant filaments which rotate regularly with constant frequency at innerwall of outer capillary distinctive discharge regime of plasma jet w hich produces a foot print of discharge symmetric w ith respect to the axis Ultimately leads to an enhanced homogeneity of deposited SiOx-films Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 40 µ-APPJ (RF-driven; He, Ar) V. Schulz-v on der Gathen, S. Reuter et al. (RU Bochum / Uni. Essen) α-mode: dominated by ionization processes in the bulk γ-mode: secondary electron emissions from electrode surface µ-APPJ and X-jet J. Benedikt, S, Schneider et al. (RU Bochum) additional helium flow steers flow of radical species into side channel Separation of (V)UV radiation and reactive species Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 41 Linear plasma jet source AcXy s Openair-Plasma (Plamatreat) Plasmatreat Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 42 Plasma and Corona treaters Dr. Gerstenberg GmbH Tigres „Korona-GUN“Plasma-Blaster Change of surface energy to improve adhesion New concept: Conplas Elektrode Hochspannung Dielektrikum Erde W erkstück Plasma Gasstrom Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 43 88 Plasma source ConPlas® Functional principle of the plasma source ConPlas®: (a) 3D-CAD model and (b) schematic side view of the plasma handheld unit, (c) plasma unit of a lab prototype in operation; 1 - isolated wires as high voltage electrodes, 2 grounded electrode, (3) - plasma, (4) - object to be treated 89 ConPlas® hand-held lab prototype Experimental setup with ConPlas® hand-held lab prototype: (a) complete treatment unit, (b) and (c) parts of the hand-held lab prototype separated from one another in different views, (d) plasma unit in operation; 1 - hand-held part with incorporated high voltage power supply, 2 – inter-changeable plasma unit, 3 - adjustable adapter between plasma unit and sample holder, 4 - plasma unit in operation Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 44 Plasma jet applications Surface treatment Pretreatment prior to painting, printing, bonding, … = Cleaning, Activation, Functionalization Coating (protective, functionalizing, ..) Etching Plasma life-science applications Biological decontamination („Sterilization“) Therapeutic applications (Plasma medicine) Detection Emission sources for analytic devices Atmospheric pressure plasmas 7. Microplasma arrays pictures composed f rom: G. Eden et al.; J. Phy s. D: Appl. Phys. 38 (2005) 1644–1648 Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 45 Microhollow cathode discharges (MHC) K.H. Schoenbach et al. Appl. Phys. Lett. 68 1, 13-15 (1996) MHC concept extends hollow cathode discharge operation to atmospheric pressure nonequilibrium plasma (Tg about 2000 K, ne: 1015cm-3 … 5 1016cm-3; Te: 0.5 – 5 eV) many similarities with a glow discharges (thin localized cathode fall region; moderate gas temperature) D: 0.1 … 0.25 mm d about 150 µm Cathode boundary layer (CBL) K.H. Schoenbach et al. Plasma Sources Sci. Technol. 13, 177-185 hole diameter D of MHC widened to about 1.5 mm varying number ofself-organized bright discharge spots, originating in the cathode fall region D about 1.5 mm d about 150 µm Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 46 MHCD as plasma cathode One of the best characterized plasma source (Puech, Graham, …) metastables densities, simulations, … Pyramidal barrier discharge J. G. Eden et al., J. Phy s. D: Appl. Phys. 36(2003), 2869 use of p-type Si(100) wafers micromachining technologies: lithographical patterning; anisotropic wet etching or reactive ion etching area of inverted pyramids: 100 x 100 µm2 down to 10 x 10 µm2 flexible arrays possible specific local power loading up to 250 kW cm-3 Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 47 Microplasma arrays Al foils or Al structures that can be covered with a thin alumina coating serving as a dielectric layer, e.g perforated 70 µm thick Al foils with Al2O3 films of 10 µm thickness S.-J. Park et al. Appl. Phy s. Lett. 86, (2005); K. Tachibana et al. Plasma Phy s. Control. Fusion 47, (2005) RF-capacitively coupled microplasmas M. C. Penache Penache, Ph.D. Thesis, U of Frankf urt 2002; N. Lucas et al. IMT Braunschweig Micro-Structured Electrode Arrays (MSEs) Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 48 Capillary plasma electrode discharge E. E. Kunhardt IEEE Trans. Plasma Sci. 28(2000), 189 - 200 one or both dielectric plates with parallel thin capillary channels frequency above a few kHz: sudden, capillary plasma jets emerge from capillary holes, overlaping and merging to a volume plasma with electron densities by orders ofmagnitude higher then those observed in diffuse BDs each hole acts as a current limiting micro-channel preventing overall current density from increasing above threshold for glow-to-arc transition. Plasma stamps N. Lucas, C.-P. Klages et al.; Proc. 3rd Int. l Workshop on Microplasmas, Greif swald, 2006, p. 180-183; Proc. 5th euspen Int. Conf erence, Montpellier/France, 2005, v ol. 2, p. 665-668. Microstructured Surface Treatment • micron-scale area-selective surface modification processes • BD-principle: patterned / structured dielectric • structure size: 150 … 500 µm (PDMS: poly dimethy lsiloxane) Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 49 New Applications µ Tachibana, Ky oto Univ ersity ; IEEJ Trans. 2006; 1: 145-155 PDP Plasma Display Panels MEMS Micro ElectroMechanical Systems TAS Total Analytic Systems Resumé Atmospheric pressure plasmas exist in a wide range of parameters (LTE and non-LTE) and configurations ... Picture: H. Kersten, Uni Kiel … with many possible and established applications. Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 50 “There are more things between anode and cathode than dreamt of in our philosophy !” [sic!] H. Raether, (1909-1986) Atomspheric plasmas and microplasmas Further reading „Non-equilibrium air plasmas at atmospheric pressures“ eds. K.H. Becker, U. Kogelschatz, K. H. Schoenbach, R.J. Bar ker; Institute of Physics Publishing: London (2005), Distributor: Francis & Taylor, CRC Press „Electrical breakdown of gases“ eds. J.M. Meek, J.D. Craggs; John Wiley& Sons: Brisbane (1978) „Fundamentals of gaseous ionization and plasma el ectronics“ E. Nasser; WileyInterscience: New Yor k(1971) „Plasma chemistr y“ A. Friedman; WileyInterscience: New Yor k(1971) „Gas discharge physics“ Yu.P. Raizer; SpringerVerlag: Berlin (1991) J.R. Roth „Industrial Plasma Engineering”, Vol. 1 and 2, IOP Publishing Ltd 1995 Ronny Brandenburg (INP Greifswald) Innolec Lectureship Brno 2012 51 Atomspheric plasmas and microplasmas Further reading K. Tachibana: “Current status of microplasma research” IEEJ Trans. 2006; 1: 145-155 F. Iza et al.: “Microplasmas: Sources, particle kinetics, and biomedical applications” Plasma Proc. and Polymers 2008; DOI: 10.1002/ppap.200700162 U. Kogelschatz: “Atmospheric-pressure plasma technology ” Plasma Phys. Control Fusion 46, 2004; B63-B75 A. Fridman, A. Chirokov, A. Gutsol : “Non-thermal atmospheric pressure discharges” J. Phys. D- Appl. Phy s. 38, 2005; R1-R24 H.-E. Wagner, R. Brandenburg, K.V. Kozlov et al “The barrier discharge: basic properties and applications to surf ace treatment” VACUUM 71, 3, 2003; 417-436 M. Laroussi and : “Arc-Free Atmospheric Pressure Cold Plasma Jets: A Rev iew” Plasma Proc. and Polymers 2007, 4, 777–788 DOI: 10.1002/ppap.200700066 U. Kogelschatz: “Applications of Microplasmas and Microreactor Technology ”; Contrib. Plasma Phys. 47, No. 1-2, 80 – 88 (2007) / DOI 10.1002/ctpp.200710012 E. E. Kunhardt “Generation of large-v olume, atmospheric-pressure, nonequilibrium plasmas IEEE TRANSACTIONS ON PLASMA SCIENCE, 28, 1, 2000; 189-200