Sharp Corp. said Monday that research by the firm shows its air purifying technology is able to reduce airborne novel coronavirus particles, claiming it as a world first.
The Osaka-based electronics maker said its Plasmacluster technology, which emits positive hydrogen ions and negative oxygen ions through plasma discharge, cut concentrations of novel coronavirus particles by about 90 percent in an experiment jointly conducted with Nagasaki University and Shimane University.
Since the research was conducted on a small scale and in a controlled environment, it remains unclear how effective the technology would be in a real-life setting.
While Sharp said its test was the world’s first to demonstrate an inhibitory effect on the airborne virus through an air purification technology, a few other Japanese makers have conducted similar experiments.
In July, Panasonic Corp. and Daikin Industries Ltd. said their air purification technologies could inhibit the virus when attached to a surface (as opposed to Sharp’s airborne particles). But since their experiments were also conducted in small-scale controlled environment, how effective the equipment can be under everyday conditions is unclear.
Still, the makers have seen rising demand for air purifiers in the past several months. According to the Japan Electrical Manufacturers’ Association, the shipment value of such products between April to July jumped about 71 percent, to ¥14.9 billion, compared to the same period in the previous year.
Researchers for Sharp’s experiment sprayed a solution containing the novel coronavirus into a three-liter apparatus equipped with a Plasmacluster device. The aerosolized solution was then retrieved after being exposed to ions for 30 seconds to check for an inhibitory effect.
The infectious titer in the retrieved solution was reduced by 91.3 percent compared with one that was not exposed to the ions, Sharp said.
“Based on the result of this experiment, we will consider and provide effective uses of the Plasmacluster technology to mitigate the risk of coronavirus infection,” said Masahiro Okitsu, who heads the smart appliances and solutions division at Sharp.
He said the next step was to conduct a test that more closely simulates a real life environment.
The positive hydrogen ions and negative oxygen ions emitted by Plasmacluster devices are said to adhere to the surfaces of airborne viruses, fungi and other substances. According to Sharp, the ions then bond and become hydroxyl radicals that can inhibit viruses by removing hydrogen from proteins through their oxidizing power.
Asked if Plasmacluster air purifiers already available on the market can help reduce concentrations of the novel coronavirus in the air, Jiro Yasuda, a professor at Nagasaki University, said the effectiveness would depend on the level of ion concentration but that they are probably effective “to a certain degree.”
In the experiment, the concentration of ions — 10 million per cubic centimeter — was significantly higher than that found in real-life scenarios. Sharp said the concentration of ions emitted through existing products was about 1 to 2 million per cubic centimeter, even in the immediate vicinity of purifier outputs.
While the experiment has proved effective, Okitsu said Sharp does not plan to directly use the result for marketing purposes due to legal restrictions. To advertise an inhibitory effect on the novel coronavirus, products would need to be officially recognized as medical devices, which Sharp said is not an easy task.
Plasmacluster technology is included with Sharp’s air purifiers and other home electronics products such as air conditioners and refrigerators.