Analysis of the physical and microbiocidal characteristics of an emerging and innovative UV disinfection technology

Abstract

IntroductionSurface disinfection is one of the key points to reduce the risk of transmission both in healthcare and other public spaces. A novel UV-chip disinfection technology is presented. Technological, photonic and microbiocidal characteristics are evaluated taking as reference an ultraviolet-C (UV-C) LED source of equivalent radiant power.MethodsThe UV chip has a circular radiating surface with a diameter of 1.3 cm, emitting UV cold light at about 5 mW and driven current of about 80 µA. Four bacterial strains were used to conduct the microbiological tests at 4°C and 60°C to evaluate the bactericidal performance of the two technologies under the same operating conditions.ResultsSpectral differences were found between the UV-C LED and the chip, with an emission curve strictly around 280 nm and a broader band centred around 264 nm, respectively. Between-technology microbiological inactivation levels were comparable, achieving total abatement (99.999%) in 8 min at 7.5 cm.DiscussionThe UV chip exhibits unique properties that make it applicable in some specific contexts, where UV-C LEDs present the most critical issues. Besides, it is portable and exhibits a broad spectrum of UV wavelengths with a peak where the maximum microbiocidal efficacy occurs. Important issues to be addressed to improve this technology are the high voltage management and the too low energy efficiency.ConclusionThis cold emission technology is virtually unaffected by changes in ambient temperature and is particularly useful in short-distance applications. Recent developments in technology are moving towards a progressive increase in the chip’s radiant power.