Are homegrown biomaterials the answer to facemask shortages?

With all the issues that have arisen in the wake of the COVID-19 crisis, problems surrounding personal protective equipment (PPE) are some of the most reported.

From badly fitting equipment for women on the frontline, to otherwise non-medical companies (like Apple) diverting their supply chains to address shortages, the lack of appropriate PPE is a serious issue for a world facing a global pandemic.

But the dependence on disposable, often plastic-based, PPE is also at odds with people trying to reduce their impact on the planet – and it is these two issues that bio-designers Garrett Benisch and Elizabeth Bridges from Sum Studio aim to tackle with their newest product design: the Xylinum mask.

“Water, tea and sugar”

As Benisch and Bridges state, the natural world is rife with “filters membranes and woven barriers that are ready to be utilised or mimicked”. With this in mind, the bio-designers took to their “home quarantine kitchen” to create the Xylinum mask.

The aim behind the project, they say, was not just to show how naturally-occurring processes might be manipulated into practical products, but prove also how accessible the process can be.

Bacterial cellulose, the material that makes up the Xylinum mask, is created by a common bacteria called xylinum acetobacter, and forms on the surface of the liquid they inhabit. While it sounds more like the work of a laboratory or school science class, the bacteria and its resultant material can actually be grown from a small sample with as little as water, tea and sugar.

Making it breathable

By “feeding” the bacteria with these ingredients, Benisch and Bridges have created a “knitted cellulose fibre” membrane, which when harvested and dried as a flat sheet, can be used as a workable material.

In order to make this material more comfortably breathable, the pair envision using a technique developed by Virginia Tech biomedical engineers Paul Gatenholm and Rafael Davalos. The technique works by placing wax particles on the growth surface and forcing the bacteria to “knit” around them, thereby creating microscopic, breathable holes.

So like the N95, the Xylinum mask would boast a tight web of fibres that provide a barrier to pathogens. But unlike the N95, it could easily degrade into the environment once it had been used.

While the whole process takes around two weeks to complete, the pair say that with the right staggered scaled manufacturing process, this could easily present a solution to the supply chain bottleneck currently impacting countries’ COVID-19 responses.

“A major material advantage” over traditional PPE

The translucency of the bacteria-based mask is also a positive feature. As Design Week reported last month, there is often a significant communication barrier to overcome with traditional PPE, since it necessarily obscures the wearer’s mouth and much of their face.

In a write up of the project, Benisch and Bridges explain that the Xylinum mask offers a major material advantage when used as a facemask thanks to its transparency.

“The expressions on the face of the person wearing the mask can be easily seen, allowing them to better connect with others,” they say, adding that this is of particular benefit also to those who are hard of hearing and rely on lip reading as a part of communication.

“Our future relies on moving forward with nature, not against it”

At present, the Xylinum mask is still a prototype, but as Benisch and Bridges explain, there are considerable possibilities for how it could be rolled out.

“This material could be grown in local municipalities, in people’s homes, or even within the very hospitals that need them to slash existing supply chain risks,” they say, adding that because of the compostability of the designs, they could easily be left to decompose with household waste, rather than impacting the environment for years to come as plastic-based PPE threatens to do.

The pair ends: “As we are kept in our homes, our entire species halted by a natural being too small to see, there is no doubt that our future relies on moving forward with nature and not against it.”