Microplasma-assisted manipulation of intact airborne bacteria for real-time autonomous detection

Lead Research Organisation: University of Glasgow
Department Name: School of Physics and Astronomy


In this project we are proposing a new method of directly detecting airborne bacteria. In many fields, the dangers of infection by pathogens, for example anthrax, need to be faced and there are major challenges with existing techniques in quickly assessing the danger so that rapid public safety responses are possible . Current techniques may be slow, expensive or need trained people and specialised laboratories. We want to devise a detection technique based on accurate measurement of a number of physical characteristics of bacteria that will allow differentiation of even similar strains so that the true pathogens can be clearly identified. This is a difficult challenge and further, we aim to show in our proof of principle, that it will be possible to design a detector that is low cost, reasonably portable and can work autonomously i.e. without continuous human intervention. Success would then encourage the development and deployment of this remote monitoring technology in critical public spaces, for example large public events and hospitals.
Description To date,
1. novel understanding of how to use aerosols as a moderator to control charge deposition onto an encapsulated target, by firing the aerosol through a discharge plasma
2. a new approach to calculating the diffusion properties of (charged) aerosols and dust in gas-plasma mixtures
3. new insight into the enhanced chemistry possible in aerosolised, charged droplets
Exploitation Route given that we are engaged in building a novel real-time airborne bacteria warning system, this will be of huge interest to the biohazard community, sensors, medicine, military etc. The enhanced chemical pathways possible in charged aerosols are hugely significant as novel nanofabrication techniques; the biocidal promise of plasma-treated droplets has myriad applications in biosciences and medicine. The underlying innovation in charging droplets in this way is still being explored: we have accrued a significant data set that requires patient analysis and modelling, and we are not yet finished.
Sectors Agriculture, Food and Drink,Education,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Security and Diplomacy

Description Whilst the grant is formally over, the impact continues. The experimental techniques developed during this grant have been harnessed for the synthesis of nanoparticles in aerosols, after being passed through a plasma. This is a wholly novel approach, with great promise for alternative methods of manufacturing in applied contexts. Additionally, the theoretical modelling associated with this project has helped us understand how to combine fluid and plasma instabilities in a unified approach to multi-phase plasmas, which may help with plasmas in general, but also in remote sensing of charged droplets.
First Year Of Impact 2016
Sector Chemicals,Environment,Manufacturing, including Industrial Biotechology
Impact Types Cultural,Societal,Economic

Description standard grant
Amount £344,732 (GBP)
Funding ID EP/N018117/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 04/2016 
End 03/2019
Title Novel approach to using aerosol droplets as charging moderator 
Description using liquid droplets containing bacteria (or any other desired target), these can be fired through a plasma to acquire charge. The precise charge deposited on the encapsulated target is controlled by evaporation, using the Rayleigh instability to determine the final charge. 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact Publication is being refereed at the moment 
Title precision charging of microparticles using charged liquid evaporation 
Description In this modelling analysis we describe a novel method for delivering a precise, known amount of electric charge to a micron-sized solid target. Aerosolised microparticles passed through a plasma discharge will acquire significant electric charge. The fluid stability under evaporative stress is a key aspect that is core to the research. Initially stable charged aerosols subject to evaporation (i.e. a continually changing radius) may encounter the Rayleigh stability limit. This limit arises from the electrostatic and surface tension forces and determines the maximum charge a stable droplet can retain, as a function of radius. We demonstrate that even if the droplet charge is initially much less than the Rayleigh limit, the stability limit will be encountered as the droplet evaporates. The instability emission mechanism is strongly linked to the final charge deposited on the target, providing a mechanism that can be used to ensure a predictable charge deposit on a known encapsulated microparticle 
Type Of Material Computer model/algorithm 
Year Produced 2016 
Provided To Others? Yes  
Impact A deeper understanding of the behaviour of charged liquids is gained by our research group, prompting further investigation of the chemical impact of lacing free droplets with significant numbers of free electrons. 
Description Collaboration with NIBEC 
Organisation Ulster University
Country United Kingdom 
Sector Academic/University 
PI Contribution Collective endeavour to study charged aerosol dynamics in plasma, with a view to harnessing this as a way of detecting bacteria
Collaborator Contribution Experimental skills and equipment
Impact Various conference papers and invited lectures
Start Year 2013
Description Sankaran Lab USA 
Organisation Case Western Reserve University
Country United States 
Sector Academic/University 
PI Contribution Joint research into droplet transport through low temperature plasmas for biomedical and materials applications. We share equipment and specialised expertise on the in-situ measurement of plasma impedance, along with modelling for joint publication.
Collaborator Contribution We share equipment and specialised expertise on the in-situ measurement of plasma impedance, along with modelling for joint publication. We use complementary configurations and diagnostics instrumentation, with impedance measurement using shared instrument as benchmark
Impact Initial data for analysis
Start Year 2018