Low-temperature atmospheric plasma (LTP) is widely used in industrial processes, such as disinfection, surface modification and wastewater treatment. The dielectric barrier discharge (DBD) is regarded as one of the most robust and reliable methods for generating LTP in ambient air. Compared to conventional AC excitation, pulsed powering offers several advantages (i.e., lower energy use and heat production). The present trend is to use short and fast pulses (in the nano- and picosecond range). In this review, the key design parameters of a DBD (barrier thickness, relative permittivity and gap distance) are discussed. Material-specific phenomena like surface charging and degradation are analyzed. The complex interactions between the pulse source and DBD are examined. By mapping the interdependencies, this review aims to support the rational design and optimization of pulsed DBD systems, and to facilitate their broader industrial use. ... Read more

Seed production is a vital part of the global food supply chain. Seed surfaces are often contaminated with pathogenic fungal spores and bacteria, which cause plant diseases during germination. These pathogens prevent healthy crop growth and reduce yields by up to 40% in major crops. The future use of pesticides will be restricted by increasingly stringent regulations, while the demand for healthy crops continues to rise. Therefore, there is a growing need for eco-friendly technologies to inactivate seed-borne pathogenic microorganisms, without compromising seed quality. Cold atmospheric plasma (CAP) offers a promising alternative. Generated in ambient air, CAP is an ionized gas containing electrons, photons, ions, and reactive oxygen and nitrogen species (RONS). It does not leave toxic residues. Although CAP has demonstrated effective microbial inactivation at laboratory scale, its industrial implementation remains limited due to challenges in scalability, reliability and heat production. In this study, these limitations are addressed by developing and optimizing a wire-plate dielectric barrier discharge (DBD) for CAP seed disinfection, powered by high voltage pulses. The seed disinfection efficacy of the DBD was evaluated for cabbage and carrot seeds contaminated with bacteria (Xanthomonas campestris pv. campestris (Xcc) and Xanthomonas hortorum pv. carotae (Xhc)) and fungal spores (Alternaria brassicicola). Key parameters (such as treatment time, operating voltage and seed positioning) were investigated. The individual contribution of several plasma components (such as accelerated ions, RONS, pulsed electric fields) to seed disinfection was examined. Our results demonstrate that a large-area pulsed wire-plate DBD can achieve effective disinfection, while no reduction in seedling growth was observed. This highlights its potential as a scalable and sustainable alternative to conventional seed disinfection methods. ... Read more

Cold atmospheric plasma (CAP) is widely used in domains such as disinfection, surface treatment and food preservation. When generated in air, CAP is rich in reactive oxygen and nitrogen species (RONS), such as ozone (O3). A dielectric barrier discharge (DBD) is a reliable method to create CAP. We developed a double-sided (twin) surface DBD with novel ‘interfractal’ electrode geometries. This fractal configuration creates stronger electric fields than the customary interdigital line geometry. So, CAP is produced more effectively, resulting in higher RONS concentrations. The performance of interfractal electrodes was compared to that of interdigital electrodes (IDE) in atmospheric air. Nanopulsed powering was used, since it is the most efficient for powering DBDs. Electrical and chemical characteristics (such as ozone level) were assessed. The results show that interfractal electrodes enhance the electric field, conduction current and ozone yield. ... Read more

This study demonstrates a breakdown analysis of the dynamics of a liquid crystal elastomer (LCE) including quality check, geometric measurement, thermal characterization, and comparison of heat- and light-induced contractions. A blue light-responsive acrylate side chain LCE with 1% azobenzene dye was characterized. From a classical viewpoint, photo-thermal contraction is considered a dominating effect, while direct photo-mechanical deformation can be neglected due to a low dye percentage. However, the findings of this research suggest that a low percentage of azobenzene dye does not necessarily lead to heat-dominating dynamics of LCE. This phenomenon has not yet been quantitatively studied before. The approach reported in this Letter can potentially be used to extract the data to improve the dynamics models of light-driven LCEs. ... Read more

Micro-devices that use electric fields to trap, analyze and inactivate micro-organisms vary in concept, design and application. The application of electric fields to manipulate and inactivate bacteria and single-celled organisms has been described extensively in the literature. By contrast, the effect of such fields on viruses is not well understood. This review explores the possibility of using existing methods for manipulating and inactivating larger viruses and bacteria, for smaller viruses, such as SARS-CoV-2. It also provides an overview of the theoretical background. The findings may be used to implement new ideas and frame experimental parameters that optimize the manipulation, sampling and inactivation of SARS-CoV-2 electrically. ... Read more