Ultraviolet light has been used for more than 30 years as a source of disinfectant. A newly introduced product uses the technology to eliminate bacteria on cell phones, tablets and other mobile devices in 20 seconds, and is used worldwide in healthcare facilities, biotech manufacturing plants, and even food processing facilities.
The CleanSlate UV Sanitizer can eradicate 99.9998 percent of Methicillin-resistant Staphylococcus aureus (MRSA) in 20 seconds. The device does not require any training to use and disinfects without the harsh chemicals that can damage electronics.
“UV light is being incorporated in different types of technologies for the purpose of disinfection,” says Josée Shymanski, manager of infection control at Montfort Hospital in Ottawa, ON, Canada. “Using UV light to target mobile device disinfection filled a need that existed, and which will continue to exist as we move more and more towards electronic technologies in healthcare.”
The Science of UV
The CleanSlate UV Sanitizers uses UV-C light, which has a wavelength of 100–280 nm. UV-C light, which is normally blocked by the ozone layer, can be used to deactivate bacteria, viruses and spores.
The UV-C light disrupts the DNA of pathogens, destroying their ability to function and replicate. The light does not physically remove the cell, but causes damage to the nucleic acid of microorganisms, preventing the DNA from being unzipped for replication. The organism is unable to reproduce; when it tries to replicate, the organism dies.
Manju Anand, chief technology officer for CleanSlate UV, says in the company's early stages, the team conducted extensive research to identify the list of pathogens that are most commonly found in healthcare facilities causing healthcare-acquired infections. “With the help of research publications, we identified the minimum required dosage to achieve the desired kill rates for the selected pathogens. The hardest one was Clostridioides difficile (also commonly known as C.diff),” Anand says.
The company developed a modular UV test chamber with the flexibility to fluctuate light source, intensity, material and finish of the chamber. “Using a radiometer, we measured the intensity and uniformity of UV light throughout the chamber,” Anand says. “Through a number of tests, we determined the best combination of the UV source, custom coatings for the chamber surface and the size of the chamber.”
Sanitization in 20 Seconds
With the CleanSlate UV Sanitizer, the user deposits the mobile device into the machine, closes a lid, and waits 20 seconds for the device to be cleaned. Once completed, the lid opens automatically, and the mobile device can then be removed with clean hands.
The device can sanitize multiple items at once and includes RFID-enabled tracking and compliance auditing. The UV-C light does not dry out or degrade materials, which occur with chemical wipes, and it can be safely used on a variety of devices with no risk of damage.
Mobile devices are placed on a movable chamber that transports the device into a UV chamber, where the sanitization occurs. The sliding chamber was a critical component, and engineers found a lubrication-free and maintenance-free solution from igus, the Germany-based manufacturer of motion plastics.
Lubrication-Free Linear Guides
The chamber includes linear guides made by igus, which runs its United States operations out of Providence, RI. The Drylin W guides slide, instead of roll, and are a cost-effective and highly flexible installation option.
“During the initial R&D stage, we discovered that the UV lights must be on and warm for effective sanitization in 20 seconds,” says Kevin Wright, the Canadian sales manager for igus. “Since the UV light is dangerous to human skin and eye, we had to design a moving chamber that transports the device into the UV chamber when the sanitization was initiated by the user. It was important to have a bearing system that was extremely quiet, especially in the evening shifts where any noise from the devices can be disturbing to the patients and staff.”
Drylin W guides are resistant to dirt and dust due to dry operation and are typically used in agricultural machinery, vehicle construction, packaging, furniture, and robotics.
“We used roller stainless steel bearings, but due to the metal contact between the ball bearings and guide, the carriage made noise that was beyond the acceptable limits in the hospital settings,” Anand says. “Furthermore, the friction caused due to non-rolling motions would result in more work for the motor, adding to stress to the system.”
Anand says in life cycle tests, the steel bearings also failed upon reaching 10–20 percent of the expected life of the product. The system could not include lubricants since the product is sold in hospital and food processing facilities.
A Growing Problem
Mobile technology is everywhere these days, especially in healthcare settings where physicians, nurses, and office personnel use devices to track and report patient progress. But devices also pose serious risks. One study reported that 94 percent of cell phones used by hospital staff bore contaminants.
“So many people come to a hospital every day; having this type of machine available for them to use reinforces the message that hygiene is important,” Shymanski says. “Combining cleaning your phone with cleaning your hands in one hygiene moment that takes 20 seconds is a good practice for your health. In addition, it shows that as an organization, we value clean care, and hopefully that translates to our patients feeling safe.”
This article was written by Matt Mowry, DryLin Product Manager for igus North America. For more information about igus, visit here . For more information about CleanSlate UV products, visit here or call 877-553-6778.