Humankind has always coexisted with various infectious diseases and germs since the inception of life. The spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus has cast a deep shadow not only on humankind but also on the world economy and people's lifestyles. Therefore, controlling all infectious diseases is a global issue for human society now and in the far future.
To inactivate viruses and germs using harmless Far-ultraviolet-C (Far-UVC) light-emitting-diode (LED) technology is inevitable for a better food to eat, water to drink, and air to breath. Farmroid’s UV technology can be used in a wide range of applications, starting in medical science and agricultural sciences.
Our Green Technology: Aluminium gallium nitride (AlGaN) based semiconductors are one of the most promising candidates for the fabrication of LEDs that would meet the requirements of Minamata Convention of 2020 [more info] the 17 sustainable development goals (17 SDGs)[more info] of the UN. Minamata Convention and 17 SDGs, to mitigate climate change, strive to eliminate the use of mercury vapor UV lamps to reduce the associated issue of CO2emission.
Earlier studies confirmed the use of UVB light of 310 nm with narrowband (NB) for cancer immunotherapy, Vulgaris treatment, and plant growth with enriched phytochemicals. Similarly, 294 nm-Band UVB light sources in the prevention of plant diseases and the production of vitamin D3 in the human body. Clean and smart DUV and Far-UVC light sources are extremely important as a disinfectant for air, water, food, and surfaces that can help to mitigate the risk of infection due to close contact with the SARS-CoV-2 and other similar viruses.
[M. Ajmal Khan, DOI: https://doi.org/10.1021/acsaelm.0c00172]
The importance of UV germicidal irradiation (UVGI) for surface, air, water, and food disinfection was already well known at the time when people were using mercury (Hg) UV lamps. After Minamata-disease, UV emitter’s researchers immediately recognized the potential benefits of compact, high-intensity, solid-state, and Hg-free sources of UV lights to respect the Minamata convention 2020 on mercury use. Recently it was found that COVID-19 changed the dynamic of the UVC LED/Far-UVC technology market. Especially, the market for UV disinfection/purification/sterilization applications emerged much more rapidly than expected in 2017. UVC LED market is expected to grow from USD 308 M to USD 2.5 B in 2025 [“UV LEDs – Market and Technology Trends” 2020 Report from Yole Développement].Therefore, recently several experimental studies were devoted to 222nm-band Far-UVC emitters, and it has been proved that Far-UVC light emitting at 222 nm is more favorable and effective for suppressing the viruses without causing damage to the human skin and eyes. Nozomi Yamano [N. Yamano, DOI: https://doi.org/10.1111/php.13269] demonstrated a world record first experiments on an animal with repeated irradiation of 222 nm emission with high disinfection capabilities[N. Yamano, DOI: https://doi.org/10.1111/php.13269]. It was found that such repeated irradiation of 222 nm does not cause any skin cancer or inflammation, and therefore it was also suggested for the safe use on human skin and eyes. During the experiments, it was discovered that all mice in the control group which were irradiated with UVB light (wavelengths of 280 – 315 nm) developed skin cancer, and many mice displayed adverse responses of corneal injuries and cataracts. UVB is the wavelength range within natural sunlight that causes skin cancer and skin burn, except NB at 310 nm emission [M. Ajmal Khan, DOI: https://doi.org/10.1021/acsaelm.0c00172]. On the other hand, no mice group developed any skin cancer, nor were any abnormalities found at the microscopic level under 222 nm germicidal lamp irradiation upon an analysis conducted with the support of the Division of Ophthalmology at Shimane University (Professor Masaki Tanito) [N. Yamano, DOI: https://doi.org/10.1111/php.13269]. These results suggest that the direct irradiation of 222 nm germicidal lamps on the human body is safe, enabling a wide range of antibacterial and viral inactivation applications in medical fields to improve the quality of life. However, Nozomi Yamano [N. Yamano, DOI: https://doi.org/10.1111/php.13269] used krypton-chloride (Kr-Cl) excimer lamp and an optical filter that restricted emission to 200–230 nm wavelengths UV, with a maximum output wavelength peak of 222 nm with full-width-half-maximum of 2 nm [Far UV-C Radiation: Current State-of Knowledge]. The excimer UVC lamp is not NB in nature, and we need an additional filter (optical bandpass) to achieve single peak spectra at 222 nm. Such Kr-Cl excimer lamp-based UVC sources are expected to be expensive compared to the environmentally friendly AlGaN-based UVC light sources. NB AlN/AlGaN/GaN-based Far-UVC LED at 222nm light sources, which are also free from toxic materials like Hg, Pb, As etc. are expected to be utilized in a wide range of antibacterial and viral inactivation applications in the medical field as well as in the agriculture field [S. Malik, DOI: https://doi.org/10.1039/D1TC03774A]. Also, NB AlN/AlGaN/GaN-based Far-UVC LED at 222 nm light sources can create many other opportunities to improve the quality of life under the recommendation of 17 sustainable development goals (17 SDGs) and WHO guideline [S. Malik, DOI https://doi.org/10.1039/D1TC03774A].