Project Summary/Abstract The potential for an epidemic or pandemic caused by a high-impact respiratory pathogen is increasing. Studies prior to the COVID-19 outbreak show that the frequency of outbreaks of newly emerging diseases rose, which has exacerbated since the pandemic started. Respiratory protective masks are used whenever airborne contaminants such as dust, fumes, smoke, and mists are present in the air. The contaminants also include airborne bacteria, viruses, and fungi. Currently, most commercially available untethered protective masks are designed for surgical or industrial safety and may provide adequate protection from airborne contaminants but do so through particle filtering. Therefore, most masks do not kill the pathogens to protect the wearers. Hence, while using an active respirator, the filtered pathogens, which are alive and infectious, may enter the respiratory tract overtime or spread by touch. The current active respirators are bulky, heavy, and designed for 2-4 hours of use. In brief, the protective masks are not designed for prolonged daily use by untrained users. Until the outbreak of COVID-19, the necessity of an anti-pathogenic wearable respirator was not as significant as it is now. This COVID-19 has exposed our lack of preparedness in providing a safe working environment for the frontline workers during the respiratory pandemic. Most current protective respirators address only part of the desired solution. A working solution needs to combine all the critical requirements, such as high filtration (≥ 99%) for nanometer-scale particles, pathogens-neutralization, moisture dissipation, eco-friendliness, and comfortable prolonged use. The proposed R&D effort addresses a wearable anti-pathogenic respirator's critical need for prolonged use by trained or untrained users. We propose designing and developing an active, untethered, anti- pathogen full-face breathing mask with an integrated photocatalytic microreactor that can neutralize all microorganisms, including viruses SARS-CoV-2. Although the proposed system contains all the components of a portable respirator, the components are miniaturized and integrated into a full-face mask. Hence, the system is referred to as a full-face mask in this proposal. The proposed full-face mask intakes surrounding air filters out particles as small as 100 nm (size of a single SARS-CoV-2 viral particle), passes the air through an integrated photocatalytic microreactor killing all the microorganisms, and volatile organic chemicals (VOCs), and supply clean air to the user. The mask also works as a defense against the threat of contamination of ventilation systems by bioterrorism. The mask is completely untethered and designed to run for 8-10 hours with a single charge. The active-powered mask can save the wearer from airborne pathogens while maintaining visibility and comfort.