Revisiting UV-C germ killing robots one year later

By Jeremy Cook

In August 2020, I wrote an article about how UV-C lighting had started to be implemented by hospitals, warehouses, and public spaces to kill SARS-CoV-2 and other microscopic organisms. Since direct exposure to UV-C can be harmful to humans, this endeavor incorporated light sources mounted on a robot to sanitize areas when humans aren't present.

One well-known attempt at UV sanitization was MIT's augmentation of an Ava Robotics telepresence chassis. It involved four UV-C lamps and created a sort of ad-hoc germ hunter-killer bot. Other companies, such as Xenex, had already explored germ-killing robotics for years and saw interest in their technology exploding. 

It's hopeful that perhaps the sanitization habits and technologies that we've developed over the last nearly two years will be here to stay in some form. But where have the cutting-edge developments that we started to see in mid-2020 gone? Have they been shelved as good PR for the time, but perhaps not as revolutionary as first thought? Or are they continuing to develop further to make the world a cleaner place? I spoke with two of the companies featured last year to find out.

MIT Warehouse Disinfection Robot (Ava Robotics)

The widely-publicized MIT Warehouse Disinfection robot was utilized in mid-2020 to disinfect the Greater Boston Food Bank (GBFB) warehouse. The device took just four weeks to set up and used an Ava Robotics Telepresence robot as the base. Following pre-defined waypoints, this robot could autonomously disinfect the warehouse and return to its dock upon completion. It was capable of disinfecting a 4000 square foot area in just 30 minutes.

In October 2020, just over a year after the initial development, Ava Robotics morphed this prototype arrangement into a standard robot setup that stands ready for disinfection. The new device features four 30W UVC lighting tubes, shoulder-mounted in two reflective pods, and can disinfect 9000 square feet per hour. A 10.2" display on the front allows for an immediate user interface. It's controlled via Ava Robotic's cloud-based Facility Manager Console. It features adaptive autonomous movement for optimal area coverage and reports disinfection results via a 2D visual presentation and automated email updates.

According to Ava robotics, while they worked with the MIT CSAIL team to collaborate on the GBFB disinfection robot, the idea of UV infection had already been under consideration for some time. While the advent of Covid-19 motivated the MIT collaboration and the robot that they now have available as a product, Ava Robotics noted this isn't new technology. Healthcare and other high-stakes environments have been using UV disinfection for some time.

Xenex LightStrike

Though UV-C disinfection isn't new, it has undoubtedly come into focus in the era of COVID-19. Xenex's LightStrike robot, as reported in the previous article, has been disinfecting high-risk areas since 2010. Their pulsed lighting technology has been evaluated in 45 peer-reviewed studies, improving on the previously-reported 35.

While Xenex had already established their robot as a product, they launched the 6th generation LightStrike unit in December 2020. These new robots can disinfect more rooms per day than previous iterations and feature more flexible customization for different rooms and better cloud functionality. The durability has also been improved, and it now features handles on both sides for easier maneuvering. Perhaps the most welcome new feature is that its wirelessly-connected safety cone, which gets placed outside of a disinfection-in-progress room, now features a countdown timer.

Since their launch in 2010, LightStrike robots have performed 30 million disinfection cycles. During the past two years, the number of facilities using Xenex robots has increased substantially, along with the total number of robots and disinfection cycles. In fact, according to their website, a disinfection cycle takes place every 5.1 seconds, making the world just a little bit cleaner each time.

Notably, the Xenex robot is manually placed into a room to be disinfected, after which the room is cleared so it can finish its cycle without humans present. The Ava robotics device features a mobile base, but similarly, the working area needs to be clear of humans to operate safely.

Fighting the Virus That Causes COVID-19

Xenex is quick to clarify that their robot deactivates SARS-CoV-2, the virus that causes COVID-19. But LightStrike, as with other devices discussed here and in the previous article, isn't used to treat COVID-19 in people. So while these robots do indeed kill the coronavirus – and prevent COVID – they don't "treat" COVID-19.

Disinfection Robots, UV-C Lighting, Here to Stay?

It appears that many improvements in light-based sanitization seen in 2020 have moved from the prototype to the product stage. But will increased sanitization and the use of UV-C lighting be with us for the long haul? While the Coronavirus pandemic is still prevalent, it's undoubtedly diminished compared to a year ago. We've crept back into regular habits, and at some point, we all want to go back to a full semblance of our everyday interactions for good.

At the same time, vulnerable areas, such as hospitals, restaurants, and transportation hubs, could potentially opt to implement and keep in place these procedures where our robotic guardians zap rooms clean at night–or during changes in occupancy. And perhaps we'll be just a little better off as a society for it. Let's hope that at least that part of our preventive measures against unseen microscopic adversaries -- SARS-CoV-2 -- and otherwise, are here to stay.