The project “Multilayer Nanofibre Filter” developed by Prof. Wallace Leung, Chair Professor of Innovative Products & Technologies of The Department of Mechanical Engineering, has been issued an US patent.
Nano-aerosols, including diesel particulates, laser-printer particles, viruses and small bacteria, by virtue of their small sizes, typically less than 100 nm, can get into our respiratory, vascular, lymphatic and nervous systems, leading to various chronic diseases. Face mask made from conventional microfibers have proven ineffective in capturing these particles. The project undertaken by Prof. Leung investigates how particle pollutants (similarly for viruses and bacteria) in air – including the nano-aerosols, especially particles less than 100 nanometers, can be captured by nanofibres, while captured viruses (also around 100 nanometers) and larger bacteria can be further killed by the functionalized nanofibre layers. The nanofibers are typically 100-300 nanometers in diameter (1/500 to 1/1000 than smaller than human hair) and can readily be made from polymeric, inorganic to natural materials. The multilayer nanofibre filter using multiple thin nanofibre layers, arranged in a stack-up of permeable scrim material with both faces each having a layer of nanofibers, attains high-capture efficiency of nano-aerosols while the air flow through the filter only requires a lower driving pressure drop as compared to the filter in which the same amount of nanofibres all packed in a single-layer. This is advantageous for many applications from personal protection (face masks, respirators) to cabin (air planes, trains, buses, and cars) and space ventilation (auditoriums, class rooms, theatres, offices, wards in hospitals, etc.).
The project has received a gold medal from 42nd International Exhibition of Inventions of Geneva and a special award from the Romania Ministry of National Education in April 2014, and international attention (New York Times featured article in April 2014 and CNN Today in Dec 2015).