Nagoya City University announced on November 24 that it has developed a photo-sterilization technology that uses visible light without using ultraviolet rays that are harmful to the human body. Ultraviolet light (UVC, light with a wavelength of 200 to 280 nm) used for sterilizing viruses and bacteria is considered harmful because it is strongly absorbed by human cells and proteins. The technology developed by Nagoya City University is to instantly irradiate visible light that is harmless to the human body.
A research group consisting of Professor Ichiro Tateno, Professor Tadao Hasegawa, and Professor Takahiro Matsumoto of the Graduate School of Design, Nagoya City University, is a momentary visible light pulse irradiation (image like flash light of a strobe). Demonstrated that it can efficiently kill viruses and bacteria. When exposed to high-intensity visible light for about nanoseconds (one billionth of a second), small viruses and bacteria instantly reach a temperature of about 300 degrees and die. Human cells are much larger, so the temperature doesn’t rise too much and it stays safe.
This method is a state-of-the-art research result that incorporates the technique of resonance excitation used in the advanced research field of laser physics into the sterilization method of pathogenic viruses and bacteria.
The research group used a proprietary “nanosecond wavelength variable pulse laser sterilizer” to irradiate gold particles that look like bacteria immersed in a solution with a pulse laser, and the gold particles reached 1000 degrees instantaneously. Dissolved. However, the temperature of the solution rose only about 2 degrees.
The high-intensity visible light pulse flash light used in this research can be easily constructed with current LED technology. In the future, it is expected to develop into hybrid lighting fixtures equipped with “pulse flash sterilization light” for LED lighting. Expected to spread to hospitals and general households.