Recent Advances in the Methods for Designing Superhydrophobic Surfaces

The investigations of superhydrophobicity and self-cleaning surfaces have been given a lot of attention in the last few decades. The surfaces having water contact angle larger than 90° are termed as hydrophobic surfaces and those which exhibit contact angle higher than 150° are said to be superhydrophobic. Such surfaces were first observed in nature in various plants and animals, for example, lotus leaf-like structures. Water repellence of various materials have shown great influences on various applications such as self-cleaning, anti-ageing, water-oil separation, water corrosion in electrical industry, water proof textiles, controlled transportation of fluids, etc. Generally, surface micro/nanostructuring combined with low surface energy of materials leads to extreme anti-wetting properties. The hundreds of research articles and more than 450 patents on the subject of nature mimicking self-cleaning surfaces prove the potential of this topic

Modeling of the effect of radicals on plasmas used for etching in microelectronics

Plazma nagrizanje predstavlja jedan od kritičnih koraka u izradi integrisanih kola. Dalja optimizacija plazma uređaja je potrebna jer nove generacije u tehnologiji zahtevaju različitu plazma hemiju. U ovom radu bavimo se uticajem radikala na plazma karakteristike, što je često zanemarivano u plazma modelima. Radikali dominiraju zahvatom elektrona čineći da je bazna smeša za nagrizanje slabo elektronegativna, a oni takođe modifikuju brzinu drifta preko modifikovanog balansa momenta. Mi smo koristili numerička rešenja Bolcmanove jednačine i Monte Karlo simulacije (MCS) za određivanje transportnih koeficijenata elektrona.Plasma etching represents one of the critical steps in manufacturing of integrated circuits. Further optimization of plasma equipment is needed since new generations in technology require different plasma chemistry. In this paper, we will study the influence of radicals on the plasma characteristics, since it was often neglected in plasma models. The radicals dominate attachment of electrons as the basic etching mixture is weakly electronegative and they also affect the drift velocity through modified momentum balance. We have used numerical solutions to the Boltzmann equation and Monte Carlo simulations (MCS) to determine the transport coefficients of electrons

Role of pressure in transport of F- ions in BF3 gas for technological applications

U ovom radu predstavili smo transportne parametre dobijene za F- jone u molekularnom gasu BF3 neophodne za formiranje globalnih modela za kompleksne sudarne plazme. Novi rezultati za set preseka i dobijeni transportni koeficijenti za F- jone u BF3 koji se mogu koristiti u takvim modelima su predstavljeni. Prvo smo koristili Nanbu teoriju za određivanje preseka binarnih sudara F- jona sa molekulima BF3. Presek za sudar tri tela uključuje egzotermni binarni presek normiran na izabrani pritisak. Koristili smo Monte Karlo metodu za dobijanje transportnih parametara na temperaturi od T = 295 K i pritisaku od 133.32 Pa (1 Torr).In this work we present swarm data obtained for F- ions in molecular gas BF3 necessary to form the global models for the complex collisional plasmas. The new results for scattering cross section set and proposed transport coefficients for F- ions in BF3 that can be used in such models are presented. First we used Nanbu's theory based on thermodynamic threshold energies to calculate cross sections for binary collisions of Fions with BF3 molecules. Cross section for three body association reaction is included by using exothermic cross section for binary reaction normalized at selected pressure. Monte Carlo method is used to obtain swarm parameters at temperature of T=295 K and pressure of 133.32 Pa (1 Torr)

Modeling of the effect of radicals on plasmas used for etching in microelectronics

Plazma nagrizanje predstavlja jedan od kritičnih koraka u izradi integrisanih kola. Dalja optimizacija plazma uređaja je potrebna jer nove generacije u tehnologiji zahtevaju različitu plazma hemiju. U ovom radu bavimo se uticajem radikala na plazma karakteristike, što je često zanemarivano u plazma modelima. Radikali dominiraju zahvatom elektrona čineći da je bazna smeša za nagrizanje slabo elektronegativna, a oni takođe modifikuju brzinu drifta preko modifikovanog balansa momenta. Mi smo koristili numerička rešenja Bolcmanove jednačine i Monte Karlo simulacije (MCS) za određivanje transportnih koeficijenata elektrona.Plasma etching represents one of the critical steps in manufacturing of integrated circuits. Further optimization of plasma equipment is needed since new generations in technology require different plasma chemistry. In this paper, we will study the influence of radicals on the plasma characteristics, since it was often neglected in plasma models. The radicals dominate attachment of electrons as the basic etching mixture is weakly electronegative and they also affect the drift velocity through modified momentum balance. We have used numerical solutions to the Boltzmann equation and Monte Carlo simulations (MCS) to determine the transport coefficients of electrons

Radio-frequency plasma in combination with aerosol injection for biomedical applications

Radiofrequency plasma for biomedical applications generated in coaxial geometry at atmospheric pressure was investigated. The plasma was characterized by key parameters, including gas temperature and electron density. It was shown that OH rotational temperature is in agreement with the temperature estimated by Rayleigh and Raman scattering techniques. RF plasma was combined with an aerosol injection for better control of the treated skin temperature and topical drugs delivery

Analysing mouse skin cell behaviour under a non-thermal kHz plasma jet

Plasma jets are extensively used in biomedical applications, particularly for exploring cell viability behaviour. However, many experimental parameters influence the results, including jet characteristics, secondary liquid chemistry and protocols used, slowing research progress. A specific interest of the presented research was skin cell behaviour under a non-thermal kHz plasma jet—a so-called cold plasma jet—as a topical skin treatment. Our research was focused on in vitro mouse skin cell direct plasma treatment with argon as an operating gas. The research was complemented with detailed gas-phase diagnostics and liquid-phase chemical analysis of the plasma and plasma-treated medium, respectively. The obtained results showed that direct plasma jet treatment was very destructive, leading to low cell viability. Even with short treatment times (from 35 s to 60 s), apoptosis was observed for most L929 murine fibroblasts under approximately the same conditions. This behaviour was attributed to plasma species generated from direct treatment and the types of cell lines used. Importantly, the research exposed important points that should be taken under consideration for all further research in this field: the urgent need to upgrade and standardise existing plasma treatment protocols of cell lines; to monitor gas and liquid chemistries and to standardise plasma discharge parameters