Functional Ultrathin Nanofilter

In an effort to slow down the spread of coronavirus, it is recommended for people to wear face masks in public. Regular surgical masks or homemade cloth masks only have 10-50% filter efficiency against particles smaller than 300 nm, which makes them incompetent to protect people from airborne viruses effectively. We are developing a fast, simple and scalable method to coat the surface of surgical masks or cloth masks with an ultrathin (< 10 nm) hybrid material, which can significantly enhance their filtration efficiency especially against virus and bacteria. Additionally, the coated masks can be decontaminated by simple light illumination, due to the photothermal property of the coating materials, which makes them reusable. If scaled globally, our technologies will solve the shortage of N95 respirators during pandemics and provide better protection against airborne biohazards.

The COVID-19 pandemic has spread to 188 countries/regions, and the total confirmed cases have exceeded 7.4 million globally, with death number exceeds 410,000. (by June 11, 2020). In an effort to slow down the spread of coronavirus, most nations are recommending their residents to wear face masks in public, some even make it a requirement. However, due to the critical shortage of N95 Masks, majority people have no choice but to wear regular surgical masks or cloth masks. Those masks are useful to filter particles larger than 300 nm, but are not efficient in blocking smaller particles, especially viruses such as SARS-CoV-2 with an average diameter of 120 nm. For instance, cotton or silk based cloth masks only have 10-50% filter efficiency against particles smaller than 300 nm, which makes them incompetent to protect people from coronavirus efficiently. In addition, currently there is no simple and effective way to decontaminate the masks, which aggravates the necessity of improving the filtration properties of face masks. 

We are developing a fast, simple and scalable technology to coat the surface of surgical masks or cloth masks with an ultrathin (~ 10 nm or 1/10000 the thickness of a copy paper) hybrid material, which can significantly enhance the filter efficiency especially against virus and bacteria. The hybrid material is based on atomically thin two-dimensional materials, which are surface functionalized and interconnected in an ultrathin polymer matrix. This hybrid network is very efficient in filtering nanometer sized particles including viruses, and at the same time allows fast transport of air and water molecules to ensure comfort of wearing, due to its compact and nanoporous structure. 
The hybrid materials can be easily spray-coated on the surface of non-woven fabrics for mask fabrication, or directly applied to regular surgical or cloth masks. This technology can be readily scaled up using roll-to-roll spay coating for mass manufacturing of the masks with our ultrathin coating. Additionally, the coated masks can be easily decontaminated by simple light illumination, the temperature of the coated layer can raise to high level (80 oC or higher) for killing of viruses and bacteria, which makes the surface coated masks reusable.

Our specific target population are healthcare workers, including doctors, nurses and researchers working with airborne viruses. We are conducting interviews among those populations in the local hospitals, nursing homes, and research institutions to better understand their needs in protection masks. Most of them expressed high desire to have face masks that are more efficient, comfortable, reusable, and at a reasonable cost.

Our technology will precisely meet their needs by providing a more efficient face masks that are compatible with current mask manufacturing processes, with one additional step of spray coating an ultrathin hybrid material on the mask-making fabrics. The coated masks are also reusable at a reasonable low cost. 

Our technology is closely related to the Health Security & Pandemics Challenge, by providing both near-term and long-term solutions. The development of more efficient and reusable face masks is essential and will provide better protection to healthcare workers and the general public. Our hybrid coating is not limited to simply blocking virus/bacteria. Active deactivation of the virus trapped on the surface of the mask can also be achieved by chemically attach antiviral and antimicrobial drug molecules to the hybrid coating. 

Most previous approaches to make a better filter or face mask are focused on the fabrics or membranes, such as using electrospinning to decrease the fiber diameter and porosity. Our approach is not to develop a new filter membrane, but to develop an ultrathin coating which can significantly improve the filtration efficiency of current filters. For face mask application, our solution has the additional advantages of being reusable by decontamination with light illumination, as well as active deactivation of virus by chemically attaching antiviral drugs to our coating layer. 

We are developing a fast, simple and scalable method to coat the surface of surgical masks or cloth masks with an ultrathin (< 10 nm) hybrid material, which can significantly enhance the filter efficiency especially against virus and bacteria. The hybrid material is based on atomically thin graphene nanosheets, which are surface functionalized and interconnected by polydopamine to form an ultrathin hybrid network. This hybrid network is very efficient in blocking nanometer sized particles, and it also has excellent antimicrobial property and stability due to the following reasons. 

Firstly, the individual graphene nanosheets have intrinsic pores of 1-15 nm diameter, which can effective block the transmission of virus and other nanoparticles. The graphene flakes are further interconnected with a polydopamine network, which is a nanoporous thin film with tunable pore size in the range of tens of nanometer, so that the transport of gas and water molecules is not affected to ensure comfort of wearing. Secondly, the polydopamine is a bioinspired adhesive material, so that the polydopamine coated hybrid network can strongly bind to the surface of respiratory masks which are made of polymeric fibers, which gives the ultrathin coating superior stability. Thirdly, both graphene and polydopamine have good antimicrobial property due to their unique morphology and surface chemistry. Last but not the least, graphene has excellent photothermal character, and under strong light illumination, the temperature of the coated layer can quickly raise to high level for decontamination of virus and bacteria, which makes the surface coated masks reusable. 

https://www.youtube.com/watch?v=T5WQXqlPU6k

Our solution paves the way for manufacturing more effective face masks and is compatible with current mask manufacturing processes. 

In the long term, our solution alleviate the anxiety and pressure in the society during potential pandemics in the future. 

Currently: 1000

In one year: 100,000

In five years: 100,000,000

In one year: Complete all the research and testing, find a industrial partner for mass production.

In five years: Commercial production by one or more face mask manufacturers, reach the global market and benefit billions of people. 

In one year: Test the performance of the product in large scale production. Find a suitable industrial partner to license our technology. 

In five years: Reach the markets in different countries and continents. 

Reach out to relevant companies and collaborate on the development and commercialization. 

Five in total

Weinan Xu, Assistant Professor, University of Akron

Gopal Nadkarni, Associate Professor, University of Akron

Pratik Kasbe, PhD student, University of Akron

Shan Liu, PhD student, University of Akron

Jenny Wong, M.S. student, University of Akron

Strong technical expertise of the professors and graduate students, as well as technology commercialization experiences of the professors.

Our solution consists of a series of innovative technologies, the SOLVE award will be mainly devoted to the development of the filter nanocoatings. Subsequent development on more advanced nanofilters with antiviral drugs attached and photothermal properties need to be supported with the larger Elevate Prize.