Most airports follow a simple template for their interiors: keep things sleek and white, with clear floor layouts that shepherd customers through duty-free aisles and onwards to rows of clothing shops, restaurants and cafés. Animating this vision are, of course, hundreds of travellers idly window shopping or staring at LED displays, watching as their flight number slowly ascends the board until their gate is announced. Milling among them, too, are a small army of cleaners and janitors that maintain the terminal space, ensuring every piece of litter is removed and every surface remains spotless.

Without these staff, it is easy to imagine that crisp, white template slowly smudging into a smattering of browns and greys under the footfall of countless travellers. Passing unobtrusively through the crowds, airport cleaners are the vanguard against the natural accumulation of dirt, bacteria and refuse that forms within these travel hubs. In wiping it all away, they remain the first line of defence in the fight against bacteria and viruses that can easily spread in spaces that thousands of passengers pass through each day.

Of course, this role has been magnified since Covid-19. As vectors for the international spread of the virus, airports now have a moral duty to protect staff and passengers in the terminal space from any new infection. Consequently, operators need to not only implement higher standards of ventilation, mask-wearing and social distancing measures, but also ensure that all surfaces are regularly purged of all virological material – something that, until recently, would have put cleaning staff in harm’s way.

Increasingly, however, airports around the world are deploying robotic assistants to mitigate the spread of the virus on surfaces and prevent their flesh-and-blood counterparts from being needlessly exposed to Covid-19. At Pittsburgh International Airport, passengers can observe these automated floor scrubbers moving across the terminal space of their own volition, cleaning the tiles below seemingly without any direction from a human operator.

“When Covid-19 hit, we started to look for ways to instil confidence in travel,” explains Katherine Karolick, the airport’s senior vice-president of information technology. It approached local technology company Carnegie Robotics, which immediately suggested retrofitting directional and sensing software, as well as UV screeners, onto their existing floor scrubbers. The new team members had the desired effect.

“The UV does seem to give the passengers a new level of confidence that pathogens are being destroyed and that disinfection is happening,” says Karolick. It’s been a particular boon for the airport, as demand for flights in the wake of the pandemic has remained low. “To be able to do that without having to add additional resources, when these resources are hard to come by right now… It’s been a great fit for [the] airport.”

Spotless automatons

Cleaning robots are not a recent invention. As early as the mid-1990s, manufacturers in Europe espied various models of autonomous vacuum cleaners from Japanese electronics companies and began adapting similar technology for use in public places. In 1996, the ST82 R Variotech made its appearance in several supermarkets in the Netherlands, silently cleaning the aisle floors as thoroughly bemused shoppers looked on. Equipped with an internal navigation system, gyroscope, sonar sensors and a simple scrubbing unit, this co-production by Siemens and Hefter Cleantech was soon making appearances in German and Austrian supermarkets too, as well as the wider interior spaces of Manchester Airport.

It was in Asia, however, that the cleaning robot would really come into its own. In 2016, Tokyo International Airport began deploying units from Cyberdyne to clean its floors, while a year later, passengers at South Korea’s Incheon Airport could spot robotic vacuum cleaners guided by light detection and ranging (LiDAR) and simultaneous localisation and mapping (SLAM) technology trundling past the duty-free aisle. By 2019, similar models could also be spotted in Beijing Daxing, Moscow Domodedovo and Changii Airport in Singapore.

The enthusiasm for cleaning robots at Asian airports would not be shared by their counterparts in Europe and North America until the emergence of Covid-19, however. The deep impact that global travel restrictions had on profit margins, combined with a tightening of social mores around hygiene, compelled many air travel hubs in the West to consider the benefits of automating parts of their cleaning regime. The idea came more easily to airports like London Heathrow, which had long used robotics to help automate processes under pressure from increasing passenger numbers.

“Prior to Covid-19, Heathrow had been operating at capacity for some time, with passenger numbers consistently on the rise while the airport’s space was constrained,” explains Mark Burgess, head of the airport’s ‘Fly Safe’ programme. As a result, “robots have been introduced and parts of the passenger journey automated to help our teams more efficiently provide outstanding customer service to our passengers”.

This includes Heathrow’s acquisition of four autonomous ‘Model B’ robots from UVD Robots and the trialling of several other automated floor cleaners, which work in concert with 100 newly trained ‘hygiene technicians’ to keep all surfaces virus-free and, in so doing, boost passenger confidence in air travel.

“The robots, which have previously been used for the disinfection of hospitals, presented an opportunity to quickly and efficiently sterilise areas within our airport,” says Burgess. “Importantly, the robots allow us to disinfect areas at a greater speed than before. Previously, it would have taken multiple cleaning operatives two or more hours to sanitise a washroom fully, due to the numerous touchpoints.”

Heathrow’s new cleaning robots can accomplish the same task in just half an hour. This is because the units are not only able to physically scrub away grime and detritus from airport surfaces, but also use a lamp resembling a mini nuclear fuel rod to emit a type of UV light known as ‘UV-C’, which kills up to 99.9% of pathogens, depending on exposure time. Entire corridors and rooms within Heathrow can be sterilised quickly using the Model B, says Burgess, albeit at the cost of forcing people to stay away while the robot does its work, lest the light damage their skin – although motion sensors switch the lamp off should anyone enter the room.

Such a trade-off is worth it, according to Burgess: “The UV-C light used by the robots is highly efficient and can disinfect 18,000m2 within a 2.5-hour time period,” he says, making such spaces safe for cleaning staff to come in and do their work.

At Pittsburgh, meanwhile, Carnegie Robotics has adopted a slightly different approach. While its autonomous floor scrubbers also use UV light to disinfect surfaces, the company has chosen to place its lamp underneath the robot and close to the ground. While this means only the floor can be sterilised, it allows for the unit to be used safely during normal business hours – all part and parcel of Pittsburgh’s campaign to increase passenger confidence in its hygiene standards.

“We’ve upped cleaning everywhere,” says Karolick, who points out that the cleaning robots at Pittsburgh are supplementing, rather than replacing, the airport’s janitorial staff. Nevertheless, she is keen to make sure that the impact of these automatons is not limited to reducing hours or appearing busy.

“We’re still figuring out our optimal cleaning method,” she explains, with researchers from Carnegie Robotics swabbing the floor for virological samples one hour, and then four hours, after one of its robots has passed over a given surface. “It’s not just about how effective the robot is in removing, disinfecting and cleaning pathogens – it’s also about how quickly those pathogens come back.”

Here to stay?

This sampling is ongoing at Pittsburgh. In the meantime, however, Karolick has noticed that the airport’s cleaning robots have had a positive effect on travellers’ morale. “Passengers interact with them, they enjoy seeing them,” she says.

Burgess has observed a similar reception among travellers at Heathrow. “We keep the robots on public display in Terminal 5 when charging, and our hygiene technicians – who are trained to answer passenger queries on the additional measures in place – have told us that they are regularly stopped by passengers commenting on the greater level of reassurance the robots provided,” he says.

But will cleaning robots become permanent fixtures in European and North American airports? Certainly, it is hard to imagine the greater societal emphasis on personal and public hygiene fading any time soon, even after the successful roll-out of a Covid-19 vaccine. Combined with the economic advantages of automating floor cleaning – a dull and dirty process that diverts janitorial staff away from responding to more complex challenges – it would appear that these automatons will survive the eventual demise of social distancing and mask wearing.

Pittsburgh has even gone as far as to personify its four UV floor scrubbers. Each is named after an aviation hero: Rosa, Amelia, Wilbur and Orville. “This isn’t going away anytime soon,” says Karolick, referring to the broader impetus the spread of Covid- 19 has had in pushing for further automation in the airports industry. “I think this is just our first step in looking at technologies that can help in this pandemic situation.”


Pathogens killed by exposure to UV-C light.