Currently, there is a significant shortage of Personal Protective Equipment, particularly face masks, due to the COVID-19 pandemic in the United States. The statistic shows that one COVID-19 patient consumes on average 17 face masks per day worn by the medical personnel. The pandemic is also affecting personnel in military and correction facilities. The post COVID-19 forecast describes that the face masks will be required long after the infection and death toll curve is flattened and declines. Wearing face masks will become a new norm for a long period of time at workplaces, shopping centers, and public events. Simultaneously, with the huge demand, face mask prices are increasing dramatically. This project is targeting the design and fabrication of a prototype of heatable and reusable face mask that can kill viruses caught on the mask surfaces thus preventing their penetration within the human respiratory system. This is achieved through resistive heating above the virus lethal temperature. A thin and breathable hater film made of engineered carbon nanomaterials will be used, which is porous and can be retrofitted or placed on the outer surface of any commercial face mask. This heatable filter is powered by a portable battery or a cell phone and is thermally insulated from facial skin. The mask can be energized when worn by the user or in storage to disinfect it. Faculties with diverse background as well as undergraduate and graduate students, and eventually some industries, will be involved in this project.
The main objective of the proposal is to fabricate and test a heatable and porous carbon nanotube air filter incorporated into a commercially available N95 respirator or other face masks that are suitable for healthcare workers dealing with pathogens. The Joule heating is generated by a thin film consisting of a few layers of carbon nanotube sheet drawn from vertically aligned carbon nanotube arrays, however other carbon nanotube sheet materials like Bucky paper can be also employed. The performance temperature directly on the surface of the porous carbon nanotube heater is designed not to exceed 85 °C, which will be enough to inactivate SARS-CoV-2. The selected breathable insulating layers will attenuate this temperature down to the harmless 37 °C when wearing the heated mask. A second mode of the mask operation is proposed here when the protective equipment after use is activated by heating for 30 seconds which will disinfect the stored mask for reuse. The objective of this proposal will be achieved by pursuing the following aims: (a) design and fabricate a breathable carbon nanotube heater that is flexible and requires low voltage for powering via a portable battery or cell phone; (b) integrate the porous carbon nanotube heater into commercial masks; (c) test the air flow rate and the effectiveness of the mask to inactivate virus surrogates, and its safety to be worn. The intellectual merit of the proposed work is seen in the merging of a porous carbon nanotube heater with a conventional face mask, thus converting it to a reusable Personal Protective Equipment, which is proposed here for the first time. This mask does not have an alternative among other commercial face protective equipment. The broader impact of this proposal can be found in the multipurpose use of the invented face mask, which is expected to be beneficial not only for healthcare providers, but also for military personnel exposed to biological weapons, as well as for the general public preventing viruses causing COVID-19. Faculties with diverse background as well as undergraduate and graduate students, and eventually some industries, will be involved in this project.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
