Ultrafast disinfection of SARS-CoV-2 viruses

TL;DR

This paper presents a rapid sterilization method for surgical masks using Joule heating with a silver and gold thin film device, achieving over 99.89% inactivation of SARS-CoV-2 within 3 minutes, maintaining mask performance.

Contribution

It introduces a novel ultrafast sterilization technique for surgical masks using a Joule heating device with thin film coatings, enabling effective virus inactivation without compromising mask integrity.

Findings

Achieved 99.89% SARS-CoV-2 inactivation within 3 minutes.

Developed a Joule heating device with silver and gold thin films for uniform heating.

Demonstrated rapid and efficient sterilization of surgical masks.

Abstract

The wide use of surgical masks has been proven effective for mitigating the spread of respiration diseases, such as COVID-19, alongside social distance control, vaccines, and other efforts. With the newly reported variants, such as Delta and Omicron, a higher spread rate had been found compared to the initial strains. People might get infected even by inhaling fewer loading of viruses. More frequent sterilization of surgical masks is needed to protect the wearers. However, it is challenging to sterilize the commodity surgical masks with a fast and effective method. Herein, we reported the sterilization of the SARS-CoV-2 viruses within an ultra-short time, while retaining the mask performance. Silver thin film is coated on commercial polyimide film by physical vapor deposition and patterned by laser scribing to form a Joule heating electrode. Another layer of the gold thin film was coated onto the opposite side of the device to promote the uniformity of the Joule heating through nano-heat transfer regulation. As a result, the surgical mask can be heated to inactivation temperature within a short time and with high uniformity. By Joule-heating the surgical mask with the temperature at 90 {\deg}C for 3 minutes, the inactivation of the SARS-CoV-2 showed an efficacy of 99.89%. Normal commodity surgical masks can be sterilized faster, more frequently, and efficiently against SARS-CoV-2 viruses and the new invariants.