ILTPC Newsletter 05 (Updated)
7 August 2020
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Table of Contents
- Call for contributions
- Images
- General interest announcements
- Meetings and online seminars
- Community initiatives and special issues (updated)
- Research highlights and breakthroughs
- New resources
- Career opportunities
- Collaborative opportunities
Call for Contributions
Please submit content for the next issue of the Newsletter. Please send your contributions to iltpc-central@umich.edu by August 31, 2020.
In particular, please send Research Highlights and Breakthroughs using this template. The highlight consists of an image and up to 200 words of text. The topic can be anything you want - a recently published work, a new unpublished result, a proposed new area of research, company successes, anything LTP-related. Please see the Research highlights and breakthroughs for examples.
Images to Excite and Inspire!
Thank you for submitting your images, some of which are shown here. Those images already submitted will appear in later Newsletters. Please do send your images (with a short description or source) to iltpc-central@umich.edu.
(Click the images to enlarge.)
General Interest Announcements
The ILTPC is maintaining a list of LTP conferences (view-only). With many meetings being canceled and rescheduled, we thought this would be useful for minimizing conflicts and planning future trips. The data may not be 100% accurate, so please let us know of changes in conference scheduling.
Contact: ILTPC iltpc-central@umich.edu
Meetings and Online Seminars
Online LTP Seminar
Reminder! Upcoming seminars: August 18, September 1, September 15.
International Online Plasma Seminar (IOPS)
Reminder! Upcoming seminars: August 13, August 27, September 10.
Community Initiatives and Special Issues
Special Issue in Frontiers in Physics on Applications of LTP in Biomedicine, Agriculture and Food Processing
Low-temperature plasmas (LTP) at atmospheric gas pressure play an increasing role in biomedical applications. The experimentally observed benefits of LTP for these applications are attributed to the controllable fluxes of chemically active species that can be produced in air at near room temperatures and delivered to bio-matter to induce desired effects. Recent research on the biomedical applications of LTP has generated new scientific knowledge regarding the interaction of plasma with soft matter including cells, tissues, seeds, and plants. The relative importance of different factors on plasma-induced bio-effects remains poorly understood. For example, cold plasma jets exhibit large electric fields that can play a synergistic role by causing cellular electroporation and thus allowing ROS and RNS (RONS) to enter the cell. The effects described above have already led to the development of many medical and therapeutic applications of LTP including wound healing, dentistry, the destruction of cancer cells and tumors. However, in order to fully utilize the potential of LTP in biomedicine, a better understanding of fundamental physio-chemical processes is required, and novel methods of precise control LTP sources need to be developed. This Special Issue aims to assemble a collection of papers on:
- Advances in understanding the ignition, generation, and maintenance of LTP at atmospheric gas pressures
- Characterization of the chemical processes which play crucial roles in the generation of RONS
- New methods for the active control of these processes for biomedical, food processing, and agriculture applications
Experimental studies, theoretical models, computer simulations, and practical applications are of particular interest. These advances can be related to the development of specific plasma-based therapies or reporting on new fundamental understanding of the physical and biochemical pathways whereby LTP affects cells and tissues.
Guest Editors:
- Prof. Mounir Laroussi
- Prof. Michael Keidar
- Dr. Vladimir Kolobov
Special Issue in Frontiers in Physics on Ion Beams from Plasmas: Space to Nanotechnology
Ion beams derived from plasmas have revolutionized many areas of physics and applications. This special issue research topic will host a collection of exciting research articles on the physics of generation and use of ion beams originating from plasmas.
More information about the overview and scope of the research topic
We cordially invite potential authors to submit high quality research papers in experimental, theoretical, and computational areas, or their combination, belonging to the broad research theme of ion beams from plasmas and their applications from space to nanotechnology. The scope may not be limited to the topics mentioned on the website alone, so long as the topic of the submitted article falls within the scope of the title.
We welcome the submission of Original Research, Review, Brief Research Report, and Perspective articles.
Submission deadline: Abstract: August 22, 2020. Manuscript: December 20, 2020.
Guest Editors:
- Prof. Sudeep Bhattacharjee Indian Institute of Technology Kanpur, sudeepb@iitk.ac.in
- Prof. Roderick William Boswell Australian National University, Rod.Boswell@anu.edu.au
- Prof. Pascal Brault Centre National de la Recherche Scientifique CNRS, pascal.brault@univ-orleans.fr
Research Highlights and Breakthroughs
Controlled Plasma-Droplet Interactions for the Quantitative Study of Multiphase Reactivity Transfer
Plasma-liquid interaction at atmospheric pressure is a complex multiphase phenomenon with inherent transport limitations of highly reactive short-lived species, such as OH radicals, from the gas phase plasma to the bulk liquid phase. In this work, we report on a highly controlled plasma-micro-droplet reactor enabling detailed and quantitative plasma-liquid interaction studies. On demand water micro-droplets containing formate are injected into a diffuse homogeneous RF glow discharge and the plasma-treated droplets are collected after pass-ing through the plasma for ex situ analysis of the reduction in formate concentration. The setup enables a 50% decomposition of formate in the micro-droplets for a short droplet residence time of ~10 ms, with minimum droplet evaporation. A 1D reaction-diffusion model, with the measured bulk gas phase OH radical density as input, is able to predict the formate decomposition without any fitting parameters. The model shows the importance of near-interfacial reactions of formate with OH radicals and the resulting diffusion limited decomposition process.
Contact: Prof. Peter Bruggeman pbruggem@umn.edu
Non-Thermal Plasma as Part of a Novel Strategy for Vaccination
Vaccination has been one of the most effective public health interventions for reducing morbidity and mortality associated with infectious diseases. Vaccines stimulate the body’s protective immune responses through controlled exposure to modified versions of pathogens that establish immunological memory. The biological effects of non-thermal plasma (NTP) on cells suggest that plasma could play an important role in improving efficacy of existing vaccines and overcoming some of the limitations and challenges of current vaccination strategies. In an immunotherapeutic strategy featuring ex vivo application of NTP, immunomodulation caused by NTP will stimulate the emission of DAMPs (damage-associated molecular patterns) from cells exposed to NTP, promote the display of new antigens, and induce de novo immune responses not triggered by the antigen alone. Therapeutic vaccination strategies involving NTP-mediated immunomodulation may also reverse or compensate for deficiencies in immune functions characteristic of some infectious diseases. Because of its capacity to modulate innate and adaptive immune responses, NTP has the potential to synergize with existing vaccination strategies.
Contact: Dr. Vandana Miller and Dr. Fred Krebs Drexel University College of Medicine vam54@drexel.edu, fck23@drexel.edu
Interfacial Pattern Between APPJ and ITO Glass Substrate
The plasma–surface interaction (PSI) is a complex pro-cess and plays a prominent and fundamental role in bio-logical applications, organic film deposition, and surface hydrophilic treatment. However, knowledge about PSI is severely limited. In particular, little is known about the mechanism of mode conversion of interfacial patterns during a PSI process. This knowledge gap is critical to plasma science, greatly hindering the future design and optimization of plasma sources for their intended appli-cations.
Here we focus on the behavior of mode conversion of interfacial patterns during an APPJ interacting with an ITO glass substrate. By regulating the pulse voltage, the results reveal that the interfacial patterns display two modes – a diffuse pattern and a streamer pattern. These two modes are not independent and can be transformed into each other by introducing additives such as N2 and O2. The reason is mainly at-tributed to the difference of N2+(B)/O(3p) ratio and local electric field distribution.
These trends for operational modes and conversion between them provide deep insights into the nature of physico-chemistry during PSI processes. These transi-tions may find potential applications in biological tissue and material treatment. However, there is still a great deal of work that needs to be done to further understand the nature of PSI in the future.
Contact: Dr. Zhijie Liu and Dr. Dingxin Liu liuzhijie@mail.xjtu.edu.cn, liudingxin@mail.xjtu.edu.cn
Source: Process Polym. 16, e1900108 (2019).
Tracking of Fast Streamer Breakdown in Pin-to-Pin Spark Discharges Driven by Pulsed HV with 200-ps Rise Time
Spark discharges ignited by unipolar positive rectangular HV pulses with 200 ps rise time and (15±2) kV amplitude with 3 ns duration (FWHM) in synthetic air in a 1.2 mm pin-to-pin gap at atmospheric pressure were investigated. The discharge development was recorded by syn-chronized ICCD and streak camera measurements with sub-ns resolution in single-shot operation revealing a particular two-stage propagation mode. The discharge started with a fast initial breakdown across the entire gap (~10 mm/ns) during the HV slope followed by a much slower (~0.1 mm/ns) propagation originating from both electrodes towards the gap centre. The combination of high-resolution diagnostics with numerical modelling indicated that the initial breakdown phase is caused by the rapid increase of electric field strength during the steep HV slope, which leads to the simultaneous fast propagation of a positive and a negative streamer.
This work was a fruitful collaboration of the Electrical Engineering Department at Eindhoven University of Technology (The Netherlands) and the Plasma Diagnostics and Modelling at INP Greifswald (Germany).
Contact: Dr. Hans Höft Leibniz Institute for Plasma Science and Technology (INP Greifswald) hans.hoeft@inp-greifswald.de
Source: Plasma Sources Sci. Technol. 29, 085002 (Open Access).
New Resources
Please submit new resources to iltpc-central@umich.edu.
Career Opportunities
Postdoctoral Positions at the University of Delaware: Computational and Experimental Plasma-Surface and Plasma-Liquid Interactions
Two postdoctoral research positions are available at the University of Delaware in the group of Professor Dion Vlachos. The first will be associated with computational work on plasma-surface interactions, plasma chemistry and plasma catalysis. The candidate should possess solid knowledge in the field of non-equilibrium plasma processing and proven record of accomplishment in plasma modelling and simulation. The second will be associated with experimental work in the field of plasma-liquid interaction for chemical conversion in the context of circular economy. The postdoctoral researcher should have strong experimental skills in plasma chemistry and plasma processing and prior experience with plasma engineering and diagnostic techniques. Additional experience in liquid chemistry and analytical methods will be considered an asset.
For more information about the post-doctoral positions, the candidates should contact Prof. Dionisios Vlachos, vlachos@udel.edu. For a description of our key catalysis and reaction engineering programs, see the Catalysis Center for Energy Innovation and RAPID Manufacturing Institute, under the Delaware Energy Institute umbrella.
Collaborative Opportunities
Please submit your Collaborative Opportunities to iltpc-central@umich.edu.
Disclaimer
The content of this Newsletter comes from the contributions of members of the ILTPC. The Newsletter editors are attempting to provide as inclusive a communication as possible. However, inclusion of items in the Newsletter should not be interpreted as an endorsement by the editors nor as advertisement for commercial purposes. The content of this newsletter should also not be interpreted as an endorsement by our sponsors – the US National Science Foundation, the US Department of Energy, or the University of Michigan. The Newsletter editors may do some light editing of the original submissions, to maintain a consistent tone and style.