As we develop a better understanding of how the novel coronavirus spreads, engineers are working to create effective, cutting-edge sterilization tech that may be able to control the transmission of the virus.
New technology that takes advantage of all kinds of cleaning methods — common chemical cleansers, ultraviolet (UV) light and techniques typically reserved for sterilizing spacecraft — is rapidly being developed or retooled for use in hospitals, hotels and public places.
Below, we’ll cover how researchers and engineers are developing sterilization technologies to help keep front-line workers safe during a pandemic.
Using Corona Discharge to Fight Coronavirus
As medical-grade personal protective equipment (PPE) like masks remains difficult to source in bulk, hospitals and other organizations face a serious challenge — how do you get the most out of the masks you already have?
Conventional sterilization methods — like steam or chemical disinfectants — often can’t fully sterilize medical-grade N95 masks. They also may make the masks less effective at protecting both the wearer and the people around them.
To extend the lifespan of medical masks, an interdisciplinary team of scientists from the University of South Florida began researching techniques that could sanitize masks without reducing their effectiveness. The team found that it is possible to use corona discharge — a kind of electrical discharge that creates a region of low-temperature plasma — to sanitize masks. The approach simultaneously deactivates pathogens while restoring the electrostatic charge of the mask’s filter, which could partially renew the mask’s effectiveness.
The team is also working on a portable, hand-held version of their corona discharge device that can sanitize homes and public places like hospitals, hotels and restaurants.
Sterilizing Hospitals With UV Light
Over the past few months, multiple hospitals, hotels and other spaces have started to use powerful UV lights — which can kill microorganisms and likely inactivate the novel coronavirus — as a sanitation method.
UV-as-disinfectant — or ultraviolet germicidal irradiation (UVGI) — is not a new approach. Typically, its use is limited to disinfecting drinking water, as UV light that is powerful enough to kill microorganisms can also damage human hair, eyes and skin. Now, however, COVID has made efficient, minimal-contact disinfection extraordinarily valuable. Chemical cleaners have also become potentially harder to access due to supply chain disruptions. These changes have made UVGI much more appealing to researchers.
For example, UVD Robots, a Danish robotics company, developed robots that use short bursts of UV light to disinfect hospitals. The robot is first steered around the hospital manually by a human pilot. As this happens, the robot builds a digital map of the hospital, keeping track of areas to sanitize. After this initial programming, the robot can operate entirely on its own, moving from room to room and disinfecting without the need for human intervention.
While it can be an effective disinfectant, not all UV light is powerful enough to deactivate pathogens. Typically, only the most high-energy category of UV — UVC radiation — is used in UV cleaners for this reason. Different UVC lights can also have different output levels — a 50-watt UVC light will outperform a 5-watt UVC model, for example. That makes measuring the output of a UV light before using it for sanitation crucial.
NASA Projects Use Peracetic Acid, Atomic Oxygen to Sterilize Masks
In late June, the National Aeronautics and Space Administration’s (NASA) John H. Glenn Research Center announced it would be teaming up with University Hospitals to collaborate on a new project. This project leverages NASA’s experience with decontaminating equipment for space flight to create new methods for sterilizing PPE, like N95 masks.
So far, the partnership has experimented with two methods of sterilization — peracetic acid and atomic oxygen.
The atomic oxygen method works by piping ozone — which is composed of three oxygen atoms — into a chamber and heating it. As the ozone heats up, it breaks down into atomic oxygen — lone oxygen atoms, common in low-Earth orbit, that can remove biological contaminants from surfaces. This atomic oxygen can effectively decontaminate masks and other items.
The second approach is a little more down-to-Earth. This method uses peracetic acid, a common chemical disinfectant, to treat used N95 respirators. Research on the technique found it was successful in killing more than 99% of viruses and bacterial spores without reducing the mask’s effectiveness.
While further research on both techniques is needed, University Hospitals said that early test results were promising.
New Sterilization Technology May Help Keep Front-Line Workers Safe
These new sterilization techniques are mostly not in widespread use yet, but they may soon shape the response to COVID-19. With masks and other protective garments still in short supply, these new methods may be invaluable in stretching existing stocks of PPE.