[Image from the University of California San Diego]
The device has worked with a number of disinfectants that have not been atomized before, like Triethylene glycol. The researchers used the device to atomize disinfectants onto environmental surfaces that were contaminated with bacteria. Results showed that the device eliminated 100% of the bacteria that are known to cause hospital-acquired infections. The researchers also used atomized bleach solution, ethanol and TEG to completely eliminate multi-drug resistant strains of bacteria.
“Cleaning and disinfecting environmental surfaces in healthcare facilities is a critical infection prevention and control practice,” Monika Kumaraswamy, a physician scientist at the University of California San Diego, said in a press release. “This device will make it much easier to keep hospital rooms clean.”
Technology used in the device also has the potential to be used in other applications as well. The researchers suggest that it could be used to deliver a new class of medicines to patients through an inhaler.
“Our goal is to make injectable treatments inhalable,” James Friend, a professor of mechanical engineering at UCSD and one of the researchers, said.
The researchers built the device using smartphone components that make acoustic waves. When used in smartphones, the parts filter wireless cellular signals and identify and filter voice and data information. In the study, the parts were used to generate sound waves at extremely high frequencies, according to the researchers. The frequencies ranged from 100 million to 10 billion Hz to be able to create fluid capillary waves that emit droplets and generate the mist in the device. The entire process is known as atomization.
Fluids are usually atomized mechanically in things like perfumes and cologne sprayers, or by ultrasound. These traditional methods that work for the viscous fluids being used and need too much power or they break down some of the active ingredients in the fluid.
Smartphone components use Lithium Niobate which produces more energy efficient and more reliable ultrasonic vibrations than the other methods. The use of the smartphone components means that the device can atomize the most viscous fluids into a fine mist that and linger in the air for more than an hour, according to the researchers.
The device worked for pneumonia-causing bacteria and on a number of multi-drug resistant strains of other pathogens. However, the researchers noted that the atomized TEG did not eliminate MRSA.
“People told us TEG kills everything,” Friend said. “Well, that’s just not true. In atomized droplet form, it was not all that effective at doing away with MRSA.”
The researchers on the project are working on building a prototype to use in hospital settings. They also suggest the device could be used in airports, airplanes and in public transportation during flu season.
The research was published in the journal Applied Microbiology and Biotechnology and was funded by the National Institutes of Health, the National Science Foundation, the Office of Naval Research and the Belmay Corporation.
