World’s First Indoor Disinfection Drone Ready To Fight COVID-19

In true timely fashion, Digital Aerolus, a global leader in autonomous technology for any vehicle that flies, drives, dives, or swims, has developed the first indoor drone with C-band ultraviolet (UVC) lights, created specifically to combat the spread of the COVID-19 (SARS-CoV-2) virus with a 99% disinfection rate.

By using its patented technologies, the Aertos 120-UVC can fly stably inside buildings and sterilize areas, thereby reducing exposure of frontline workers to infections. Digital Aerolus’ industrial drones do not use GPS or external sensors, allowing them to operate stably in places other drones cannot go – including small and confined spaces.

The Aertos 120-UVC flies above a surface that it illuminates using 36 optically intense 265 NM LED UVC lights. At 6 feet above a surface and just 5 minutes, this is enough UVC intensity to provide a greater than 99% disinfection rate of a 2 meter by 2 meter surface. These drones are scheduled to be available in volume in May.

We had a chance to interview the co-founder, Jeff Alholm, about this innovative drone technology.

Alice Ferng, Medgadget: What is the UVC power intensity needed to inactivate viruses? Can you talk more about the exposure time needed for virus inactivation?



Jeff Alholm, CEO of Digital Aerolus: We know from studies with other coronaviruses that inactivation using UVC depends on exposure time and intensity. As a general rule, delivering 3 milli-joules of 265 NM UVC to a square centimeter area will achieve a disinfection rate exceeding 99%. These results are not derived from our studies, but from those of our UVC LED supplier, Crystal IS/Klaran, and decades of pathogen sterilization using UVC energy in various industries.

De-activating the replication mechanics of a virus on a surface critically depends on the exposure time and distance from the UVC source. We mount our UVC LEDs on a moving airborne vehicle.

UVC energy emitted in the wavelength range centered around 265 NM is generally considered the gold standard for effective UVC disinfection. There are multiple variables in every disinfection situation. As a general rule, if a greater than 3 milli-Joules of energy can be delivered to a cm by cm surface, then a greater than 99% disinfection rate is achieved.

The correct UVC fluence or dose (d) is calculated using the following equation:

UVC Dose (d) = UVC Intensity (i) x Exposure time (t)

UVC Intensity (i) = Power emitted from UVC light source or sources + distance of emitters (in this application 36 emitters pointing down from the Aertos 120-UVC) toward the surface being sanitized X (times). Exposure time (t) = time of exposure.

Medgadget: What’s the UV operating frequency range, and why is UVC the most effective for this application? Was this technology based on any prior studies?

Mr. Alholm: UVC disinfection systems are broadly deployed and sanitize much of the world’s water. Drone-based UVC disinfection–our delivery of the UVC energy makes this product unique.

Disinfection via UVC emitters is not new, but there is a new class of small LED sources that have recently become available for broad deployment. Using our stable indoor platform to deliver UVC disinfection is what is unique. By combining our steady industrial drones with these small but powerful UVC sources, allows more organizations to deploy UVC disinfecting tactics quickly and remotely. We believe that some businesses and organizations need immediate, deployable, and practical access to this technology to kill pathogens.

Ultraviolet UVC in the 265-nanometer frequency range provides an extremely high rate of disinfection. There are multiple variables in every disinfection situation.

To provide a broadly applicable example, we have calculated the time and distance from the Aertos 120-UVC to accomplish a greater than 99% disinfection rate.

Here is one example to help understand the Aertos 120-UVC capabilities:



● The Aertos 120-UVC contains 36 optical intense 265 NM LED UVC sources arranged in an array pointing down from the UAV (there are options to the Aertos 120-UVC that has additional emitters pointing up).

● When the platform flies 2 meters (~6.6 feet) above a surface for three minutes, it provides higher than a 99% disinfection rate in the red center of the green box shown below, or if flown for 5 minutes, the entire 2 by 2 meter (~6.6 by 6.6 foot ) square is covered.*

● Besides just the surface, the entire area inside the Figure 1 ray tracing representation is covered, roughly 150 cubic feet.

● Similar simulations show that a greater than 99% disinfection rate is achieved over a smaller surface area by flying just 18 inches for 30 seconds.

● As a general rule, if a greater than 3 milli-Joules of energy can be delivered to a 1 cm by 1 cm surface, then a greater than 99% disinfection rate is achieved.



Medgadget: At 6 feet above the surface, how concentrated is the beam? Coherence can be a big issue.

Mr. Alholm: The simulations above are based on the data from this specific LED; it’s a lack of coherence that is helpful. The 36 emitters have a nice overlap of energy that can be seen in the surface energy density plots. Overkill is always good, more energy is best, yet this has to be balanced with sanitizing as much space as possible.

Medgadget: Can UVC inactivate COVID-19? How was this tested? Was it a partnership?

Mr. Alholm: COVID-19 is a disease caused by a new virus (SARS-CoV-2) related to other well-characterized viruses. At this time, the CDC continues to develop broad disinfection guidelines for this virus. Recent research and protocols indicate that UVC energy centered around the 265 NM wavelength is useful for COVID-19 disinfection, destroying its RNA/DNA.

UVC light sanitation technology is currently used for surface and water disinfection all over the world. As you know, UVC technology is not new. But generally, UVC sources are large, cost-prohibitive or impractical to deploy.

We are working with UVC LED manufacturer Crystal IS/Klaran, and we have worked closely to integrate their UVC emitters properly. We have not entered into a formal partnership.

We are working with the manufacturer’s engineers to determine the correct UVC doses needed for a 99% disinfection rate, and the graphics I’ve provided come from Zemax OpticalStudio software with data supplied by Crystal IS/Klaran.

At the same time, before the May production rollout of the drone, we are gathering additional data.

I want to make it clear that we are not trying to be experts on UVC or COVID-19 (SARS-CoV-2). We are engineers and scientists, not UVC experts. However, there are decades of credible research surrounding the effectiveness of UVC as a disinfection tool. We are working with proven UVC research and applying it to a new delivery application via our stable commercial drones.

Medgadget: Are there surfaces where UVC inactivation is not as ideal for or ineffective?

Mr. Alholm: We’re hoping to find out more about disinfecting varied surfaces and spaces.

For now, the Digital Aerolus team will continue to focus on delivery mechanics and processes. As soon as we can get information from additional users about how the Aertos 120-UVC tool performs in the field, we’ll improve on the most effective ways to deploy our Aertos UAVs for disinfection tasks. Hard surfaces are straight forward to characterize. Cloth and other porous materials require more time and data to describe accurately.

Medgadget: Is there any harm to people if they are in the flight path?

Mr. Alholm: Drones are sophisticated tools, and in general, require a pilot that has the skill and experience necessary to complete the desired task. Since conventional drones only fly well outdoors, deploying a drone indoors multiplies the complexity and the chance for a collision. We designed the rugged Aertos 120-UVC to withstand crashes, but there’s always the chance of a collision that damages the drone, property, or a human. Proper procedures, training, and, when appropriate licensing, should ever be observed. Our Aertos 120-UVC has protected ducts versus open spinning blade or blade with inefficient blade guards.

Also, the Aertos 120-UVC drone emits intense UVC light from 36 UVC LEDs. This frequency of this energy is dangerous to humans: it damages DNA and other organic molecules and leads to severe harm to the molecule. That’s bad for both viruses and humans. All pilots and any spectators of UVC disinfection should remain hidden from the UVC emitters while on. If around the energized emitters for any reason, then proper eye and skin protection are required. The Aertos 120-UVC is designed to be flown remotely, and the UVC emitters are wirelessly controlled during a flight to prevent the pilot from being exposed. We are all familiar with the need to wear UV sunglasses, and proper covering to achieve protection from sunlight containing UV A and B energy. UV-C is naturally filtered by the atmosphere and is significantly more damaging to our skin and DNA.

Medgadget: If any of the UVC lights go out, does the efficiency and efficacy of inactivation decrease? By how much? Will the user be notified?

Mr. Alholm: If the intensity of the UVC emitters changes, the efficiency changes. But have put 36 UVC emitters on our drone, MORE than enough power to disinfect with a 99% kill rate, so that if an emitter goes out, the disinfection will still be successful, requiring slightly more time.

By the time production launches in May, we plan on having software tools available for all customers to use so that they can determine effective doses for each disinfection.

Our Aertos system uses four strip arrays of 9x UVC 265 NM high-intensity LEDs. At any given time, a total of 36 LEDs can be illuminated. The efficiency decreases in a linear relationship depending on how many LEDs are on. We will provide periodic testing and maintenance methods, but the lifetime of these LEDs are measured in many thousands of hours.

Medgadget: Are your drones explicitly built for a certain type of indoor space? How do they navigate around barriers? Are they programmed similar to a Roomba, and similarly – does it get stuck? (If it doesn’t use GPS or external sensors – how does it navigate a new area?) Is it fully autonomous, or can manual control be used? Is there remote-controlled video feedback? Tell us more about the imaging system – are there sensors to detect infected areas?

Mr. Alholm: For these UVC applications, the Aertos will be operated in First-Person View (FPV) by a skilled pilot using the cameras on the platform. We designed our drones around a unique set of navigational and AI structures, we call these the Mind of Motion Framework and Folded Geometry flight Code (MMF and FGC). Today’s Aertos platforms operate in what we call semi-autonomous mode. Using AI techniques, we build a dynamic set of kinematic models based on the environment that the drone is experiencing, along with “watching” the pilot. These models allow us to do seemingly impossible things: feeling and backing off from wall and ceilings effortlessly, adjusting for wind or ventilation, correcting for drift and creating stability without optical flow, magnetic bearings, maps, Lidar, or GPS. We are “instant on” and can automatically balance / perch on a pipe of the edge of furniture or a fixture to significantly increase flight times during operations.

Because of their rugged construction and flight technologies, our Aertos platforms are generally difficult to get stuck. We’re not aware of any technologies that can detect micro pathogens from a distance. That would be an unbelievable advantage. We currently fly two imagers, a fixed low-resolution FPV camera, and a much higher resolution gimballed array. In other Aertos models, we have IR capabilities along with higher resolution visible spectra cameras.



Medgadget: What’s the use time for the drone (battery life)?

Mr. Alholm: Generally, we expect 10 minutes of flight time for our traditional missions but typically fly back at 8 minutes to play it safe. These times depend on many variables: the altitude and humidity of the environment, how long the UVC LED arrays are on, and how long the platform can perch. If perched or balanced operating time can be extended to over 30 minutes. Since piloting a drone is a strenuous task that requires concentration, 10 minutes of non-perching flight time is an acceptable mission.

Medgadget: How many of these have gone into production? Do you already have buyers lined up? Where will these drones be first deployed and used?

Mr. Alholm: We are currently bringing up volume production for the Aertos 120-UVC drones in May. The platform is a slight variation on a platform we sell daily, our Aertos 120 industrial drone. We have a significant distribution and support network supporting our current and future Aertos customers.

CDW will begin taking preorders and have this new product on its website this week. Besides our existing reseller network, we are talking to other potential partners and drone service providers to support our growing customer base. Yes, we have orders, and we are flying the Aertos 120-UVC today.

Medgadget: Anything else you’d like to add about the company, its goals, plans, or vision moving forward?

Mr. Alholm: Digital Aerolus’ mission is to combine artificial intelligence with advanced mathematics to create software and the base technologies for vehicles that fly, drive, dive, or swim. The company’s first commercial products using these technologies are the Aertos industrial inspection drones. This includes our newest product, the Aertos 120-UVC.

Our current and future autonomous systems equip vehicles to look at the world differently – in a predictive, and not just a reactive, way. We believe this approach will make the world a safer and more efficient place. The Mind of Motion Framework is particularly powerful: it quickly processes avalanches of input data to predict potential threats and then to effect changes based on a quickly-changing environment and risks. MMF integrates complex operators of all orientations, accelerations, velocities, probabilities, interactions, and noise. Then, it projects how the host vehicle should behave. MMF is managing the world continuously in real-time, coherently and concurrently, for vision, autonomous behaviors, various sensor data, and flight/drive operators. It maps the probability of interactions and collisions for all projected objects, including the platform, and projects a probabilistic cloud of interactions based on real physics. Other approaches to autonomous navigation management are simply at a disadvantage.

This is truly transformative. When drones are no longer limited to flying only outdoors, when robotic avatars can make intelligent and human-like decisions, when machines can perform dangerous tasks instead of people, the world is a safer place. And, we’re helping build that world.

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