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RESEARCH ARTICLE

Considerations Using Additive Manufacture of

Emulsion Inks to Produce Respiratory Protective Filters

Against Viral Respiratory Tract Infections Such as the

COVID-19 Virus

Colin Sherborne, Frederik Claeyssens*

The Kroto Research Institute, North Campus, University of Sheffield, Broad Lane, Sheffield, S3 7HQ, UK

Abstract: This review paper explores the potential of combining emulsion-based inks with additive manufacturing (AM) to
produce filters for respiratory protective equipment (RPE) in the fight against viral and bacterial infections of the respiratory
tract. The value of these filters has been highlighted by the current severe acute respiratory syndrome coronavirus-2 crisis
where the importance of protective equipment for health care workers cannot be overstated. Three-dimensional (3D) printing
of emulsions is an emerging technology built on a well-established field of emulsion templating to produce porous materials
such as polymerized high internal phase emulsions (polyHIPEs). PolyHIPE-based porous polymers have tailorable porosity
from the submicron to 100 s of µm. Advances in 3D printing technology enables the control of the bulk shape while a micron
porosity is controlled independently by the emulsion-based ink. Herein, we present an overview of the current polyHIPE-based
filter applications. Then, we discuss the current use of emulsion templating combined with stereolithography and extrusion-
based AM technologies. The benefits and limitation of various AM techniques are discussed, as well as considerations for a
scalable manufacture of a polyHIPE-based RPE.

Keywords: Polymerized high internal phase emulsions; Emulsion templating; COVID-19; Additive manufacturing;
Respirator protective equipment

*Correspondence to: Frederik Claeyssens, The Kroto Research Institute, North Campus, University of Sheffield, Broad Lane, Sheffield, S3 7HQ,
UK; F.Claeyssens@sheffield.ac.uk
Received: October 20, 2020; Accepted: November 18, 2020; Published Online: January 13, 2021

Citation: Sherborne C, Claeyssens F, 2021, Considerations Using Additive Manufacture of Emulsion Inks to Produce
Respiratory Protective Filters Against Viral Respiratory Tract Infections Such as the COVID-19 Virus. Int J Bioprint,
7(1): 316.http://doi.org/10.18063/ijb.v7i1.316

1. Introduction the integrity of the fibers and remove their electrostatic
charge. Additive manufacturing (AM) has been widely
Personal protective equipment (PPE) and respiratory utilized for various applications, such as in the fields
protective equipment (RPE) are vital for frontline health of aerospace , automobiles , and tissue engineering ,
[3]
[2]
[1]
workers that work with patients infected with contagious and now, the AM community has developed three-
respiratory tract infections, such as the coronavirus dimensional (3D) printing initiatives to support health
disease 2019 (COVID-19). During the early pandemic, care and frontline workers . This includes rapid
[4]
there was an exceptionally high global demand for RPE printable face shields for health care workers that can
but supply chains were under severe strain and supply reduce direct exposure from large airborne respiratory
continuality remained uncertain. There is a constant droplets . However, these initiatives are limited by the
[5]
demand for RPE masks as they are disposable items or material choice and technology that produces masks for
have a short lifetime as the filters need to be replaced or respiratory protection. A key component of RPE is the
decontaminated after prolonged use, which could damage filtering mechanism. The filter traps and retains airborne

© 2021 Sherborne and Claeyssens. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0
International License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium,
provided the original work is properly cited.
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