Axel Sonnenfeld

Bio: Axel Sonnenfeld is an academic researcher from University of Greifswald. The author has contributed to research in topics: Atmospheric pressure & Noble gas. The author has an hindex of 2, co-authored 2 publications receiving 789 citations.

Deposition Process Based on Organosilicon Precursors in Dielectric Barrier Discharges at Atmospheric Pressure—A Comparison

Abstract: Dielectric barrier discharges (DBD) at atmospheric pressure are presented as a tool to create organosilicon deposits on technical planar aluminium substrates (up to 15 × 8 cm2) by admixing small amounts of hexamethyldisiloxane (HMDSO) and tetraethoxysilane (TEOS) to the carrier gas of the discharges. Using barrier materials of different specific capacities (2.6 × 104 and 3.2 pF/cm2) in two electrode arrangements operated at less than 1 W, the influence of the filament properties on the deposition is studied. In comparison to these arrangements, a third electrode setup with a barrier of the specific capacity of 2.9 pF/cm2 is operated at approximately 50 W to study the influence of the specific energy of the plasma (energy per molecule) on the deposition process. The plasma chemical process was studied qualitatively by Gas Chromatography, and properties of the plasma-treated substrates were examined by means of X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) spectroscopy, as well as visually.

Airflow control by non-thermal plasma actuators

Abstract: Active flow control is a topic in full expansion due to associated industrial applications of huge importance, particularly for aeronautics. Among all flow control methods, such as the use of mechanical flaps, wall synthetic jets or MEMS, plasma-based devices are very promising. The main advantages of such systems are their robustness, simplicity, low power consumption and ability for real-time control at high frequency. This paper is a review of the worldwide works on this topic, from its origin to the present. It is divided into two main parts. The first one is dedicated to the recent knowledge concerning the electric wind induced by surface non-thermal plasma actuators, acting in air at atmospheric pressure. Typically, it can reach 8 m s−1 at a distance of 0.5 mm from the wall. In the second part, works concerning active airflow control by these plasma actuators are presented. Very efficient results have been obtained for low-velocity subsonic airflows (typically U∞ ≤ 30 m s−1 and Reynolds number of a few 105), and promising results at higher velocities indicate that plasma actuators could be used in aeronautics.

Low temperature atmospheric pressure plasma sources for microbial decontamination

Abstract: The aim of this paper is to provide a survey of plasma sources at atmospheric pressure used for microbicidal treatment. In order to consider the interdisciplinary character of this topic an introduction and definition of basic terms and procedures are given for plasma as well as for microbicidal issues. The list of plasma sources makes no claim to be complete, but to represent the main principles of plasma generation at atmospheric pressure and to give an example of their microbicidal efficiency. The interpretation of the microbicidal results remain difficult due to the non-standardized methods used by different authors and due to the fact that small variations in the setup can change the results dramatically.