New Robot System Could Disinfect 4,000 Square Foot Space in 30 Minutes with UVC: Study
Mon, April 19, 2021

New Robot System Could Disinfect 4,000 Square Foot Space in 30 Minutes with UVC: Study


Disinfection is key in eliminating bacteria, viruses, and other pathogens on items and surfaces. However, using cleaning products can be expensive, time-consuming, and dangerous to human health. So, a team of scientists developed a robotic with an ultraviolet system to disinfect items more efficiently.

The disinfecting robot has been co-developed by scientists at the Massachusetts Institute of Technology (MIT), a private research university in the US. Their model utilizes ultraviolet C type to kill pathogens on objects and surfaces. This can be more efficient in disinfecting large areas and numerous items at once, but the light emitted by the robot is not perfectly safe for people. As such, only a trained person can operate it and the target area must be cleared out.

The Impact of COVID-19 on Disinfection and Hygiene

When COVID-19 has been declared a pandemic, the medical community revealed how the disease is often transmitted between people. The most common transmission mode is via respiratory droplets emitted by someone who coughed or sneezed. These droplets are invisible to the naked eye once dispersed into the air. Because of that, health experts recommended face masks, social distancing, proper handwashing, and good hygiene to protect themselves against the disease.

The preventive measures for COVID-19 altered the behavior of millions around the world. According to Statista, a German portal for statistics, sales growth of health and hygiene products in drugstores went up quickly in the US. As of February 2020, the sales growth rates were 80.7% for hand sanitizers, 35% for cloth all-purpose cleaners, 26.6% for spray disinfectants, and 23.1% personal thermometers. Though, there was a drop in the sales of toilet tissue by 3.4% and 5.5% for facial tissue. Tissue paper sales growth was likely felt in grocery stores and supermarkets, where people could buy them in bulk.

Meanwhile, a survey conducted on 1,986 US adults, on March 13 to 16, 2020, showed the likelihood of individuals to purchase home cleaning products due to COVID-19. The results, based on gender, revealed that 41% of males would likely buy more of those products, while 49% of females shared the same intent. But 53% of males and 43% of females said they would not buy more or less of those products. About 2% of males and females said they would buy less home cleaning products, and about 4% of males and 6% of females had no idea if they would buy more or less.



The UV-Bearing Robot Disinfector to Fight COVID-19

At MIT, scientists worked with Ava Robotics and the Greater Boston Food Bank (GBFB) to design a novel robotic system to fight the pandemic. This robot has been equipped with ultraviolet light emitters to effectively disinfect surfaces and even neutralize the aerosolized forms of SARS-CoV-2, the virus of COVID-19. With its capability, the robot is expected to be more efficient in disinfecting items than the use of cleaning products.

According to the World Health Organization of the United Nations, ultraviolet radiation is deadly enough to affect living organisms, large or microscopic. But its influence on living organisms depends on the wavelength. Wavelength is the frequency of a wave that determines how fast it is moving. The shorter the wavelength is, the more harmful ultraviolet light is. In relation to the human body, shorter wavelengths are less able to penetrate the skin.

Ultraviolet wavelength is divided into three main types as identified by science. These are ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). UVA has the longest wavelength and can penetrate the middle layer of the skin. UVB has the median wavelength among the three and can penetrate the skin's outer layer. UVC, on the other hand, has the shortest wavelength, filtered completely by the Earth's atmosphere, and cannot penetrate the skin's outer layer in spite of its strength in irradiating living organisms. Though, science cannot guarantee that the skin will absorb UVC without suffering from damage, especially in extended periods of exposure. Thus, the application of UVC still involves health precautions to avoid consequences.

In the study, the goal is to assist disinfection protocols in critical sectors, such as food and manufacturing. These sectors often require warehouses for storage but such areas are at risk of contamination with the number of activities occurring in a single day. Although chemical cleaners are excellent in killing microbes, the active ingredients in those products can also affect human health. What if UV light can be deployed in warehouses to disinfect objects and surfaces in seconds?



"Food banks provide an essential service to our communities, so it is critical to help keep these operations running. Here, there was a unique opportunity to provide additional disinfecting power to their current workflow, and help reduce the risks of Covid-19 exposure," said Alyssa Pierson, technical lead of the UV-C lamp assembly and scientist from the Computer Science and Artificial Intelligence Laboratory at MIT.

At a glance, the robot looks like a modern pedestal with five rods on top. Four thinner rods surrounding the center rod served as emitters of UV. But a closer inspection of its specifications shows the robot's ability to map the surrounding. Mapping the surrounding allows the robot to measure the size of an area and create navigation points. Also, the robot is equipped with a UVC dosimeter to emit the expected dosage of radiation in an area.

The unit was tested in a warehouse of GBFB to determine its performance and efficiency. The assessment showed that the robot could drive by the pallets and aisles. It navigated through these obstacles at a speed of about 0.22 miles per hour. Scientists translated that speed to a coverage of 4,000 square feet of space in the warehouse in 30 minutes. The dosage delivered during that navigation neutralized 90% of coronaviruses on surfaces. But the dosage could be higher to neutralize more viruses.

UV light for disinfecting objects and surfaces has several advantages over cleaning products. First, it neutralizes pathogens including those with antimicrobial resistance in seconds. Second, it does not leave a residue after disinfecting items and spaces, which means no additional measure is required. Third, it can sterilize objects as well. Both disinfection and sterilization are decontamination methods but the latter is more focused on killing microbes. And fourth, it can disinfect crannies and nooks as long as light can bounce off and onto surfaces.

The novel robot unit has been tested initially via teleoperation. Scientists are now investigating the use of onboard sensors to enable the unit to learn more about its surroundings. These sensors are essential in analyzing the details of new territories.