Identification number: Nr.1.1.1.1/21/A/050

Type: ERDF

Project duration: 01.01.2022 - 30.11.2023

Project manager: Dr.hab.phys. Juris Purāns

Partners:

  • Latvian Biomedical Research and Study Centre (LBMC)
  • SIA SIDRABE Vacuum

Total funding:

The total budget is 500 000 EUR with ERAF contribution of 425 000 EUR.

Project aim:

The aim of this industrial research project is to develop advanced roll-to-roll (hereinafter R2R) physical vapour deposition (PVD) technology for large scale production of a new type of multifunctional antibacterial and antiviral (MABAV) coatings. We propose to produce and investigate MABAV materials in the form of thin films and multilayers with photochromic and transparent conducting multifunctionalities based on rare-earth oxy-hydrides (REHO) and metal oxides (MO) in combination with the metal and other dopants.

Project summary:

COVID-19 pandemic calls for new ways to combat pathogen resistance. The pathogens can persist on several types of surfaces long enough causing transmission of various infectious diseases [1], which are a continuous threat to human health and have a negative impact on the economy. The hospital environment is the epicentre of most antibiotic-resistant infections, especially respiratory pathogens, and where outbreaks occur. According to the European Centre for Disease Prevention and Control, more than four million people are estimated to acquire a healthcare-associated infection (HCAI) every year in Europe [2]. In addition, antimicrobial resistance towards antibiotics is growing everyday due to environmental changes and microbial adaptation abilities. For these reasons, the development of advanced solutions is urgently needed today. The knowledge on the survival of bacteria, fungi, viruses, and protozoa on surfaces, and hence, in a broader sense, in the human environment, is important for planning and implementing tactics for prevention of HCAI [3].

Within the framework of this industrial research project an advanced roll-to-roll (hereinafter R2R) physical vapour deposition (PVD) technology for large scale production of a new type of multifunctional antibacterial and antiviral (MABAV) coatings will be developed. MABAV materials in the form of thin films and multilayers with photochromic and transparent conducting multifunctionalities based on rare-earth oxy-hydrides (REHO) and metal oxides (MO) in combination with the metal and other dopants will be produced and investigatd.

Applications: smart windows/glass, smart foils/sheets (as partitions and barriers in public places) and transparent electronics applications, including medical devices, with the aim to prevent the diseases in terms of reduction of bacteria and virus prevalence with attention to the SARS-CoV-2 to limit and reduce the spread of this virus and consequently caused illness COVID-19.

This project will be implemented by the Institute of Solid State Physics of University of Latvia (ISSP UL), a vacuum coating SME company SIDRABE Vacuum Ltd (SIDRABE) and Latvian Biomedical Research and Study Centre (LBMC). This interdisciplinary project consists of the research activities in Physical (1.3), Chemical (1.4) and Biological (1.6) sciences, and Materials engineering (2.5).

[1] Journal of Hospital Infection 99 (2018) 239-249.
[2] European Centre for Disease Prevention and Control. Point prevalence survey of healthcare-associated infections and antimicrobial use in European acute care hospitals 2011–2012. Stockholm: ECDC; 2013.
[3] Coatings 9 (2019) 654.

Expected scientific results:

  • Novel R2R deposition technology of MABAV coatings on flexible substrate (results: new technology, patent);
  • Novel REHO and MO thin films and multilayers with advanced MABAV properties (results: scientific articles, new product prototype, patent).
 
 

Project progress information

Period: 01.01.2022.- 31.03.2022. | March 31, 2022

At the beginning of the project, ISSP prepared the thin-film magnetron sputtering equipment, compiled the procurement list of the required metallic and alloyed targets, and did first characterization of the fabricated coatings:

Optimization of magnetron sputtering process, preparation of first single-layer (Cu, ZnO, WO) and multilayer (WO3/ Cu/WO3, WO3/Cu/W/WO3, ZnO/W ZnO) coatings.

  1. A list of targets to be obtained for the development of innovative single-layer and multi-layer MABAV coatings on glass and plastic sheets has been established:
    • Gold (Au) wire, 1 gram, 99.99% purity, 1.0 mm diameter
    • Silver (Ag) wire, 1 foot, 99.99% purity, 1.5 mm diameter
  2. UV-VIS-IR spectroscopic measurements of transparent conductive thin films to determine the reflectance, transmission and absorption spectra of the films.
  3. Spectroscopic ellipsometry measurements of transparent conductive thin films to evaluate film thickness and quality (dispersion curves of optical constants, band gap, optical gradient, surface roughness).

SIDRABE has adapted the roll-to-roll (R2R) equipment for the sputtering of the thin films required in the project:

  1. Tightness and necessary high vacuum condition of the sputtering chamber have been checked, and found shortcomings have been rectified.
  2. Magnetron cooling system was cleaned and checked for leaks.
  3. Conditioning of the film winding system has been made and stability improved.
  4. W and Cu magnetrons have been installed to allow the first coatings to be formed in the pilot mode.

To evaluate the antiviral and antibacterial properties of novel nanocoatings  the testing methodology was established according to EN ISO 1276 and EN ISO 16615 and approved by LBMC on the first samples obtained from ISSP:

  1. Currently, the protocol is optimised for gram-negative and gram-positive bacteria cultivation: Escherichia coli, Staphylococcus aureus.
  2. Preliminary data on biocidal activity of tungsten oxide containing nanocoatings have been obtained.
  3. Furthermore, to evaluate the antiviral activity of nanocoatings, several model viruses have been selected: Semliki forest virus (mammalian enveloped RNA virus), MS2 bacteriophage (RNA non-enveloped virus), Pf1 bacteriophage (circular single-stranded DNA filamentous virus). The respective viruses were produced and quantified.