PU30™ Antiviral, Washable & Reusable Face Mask is developed by PolyU in 2020 in order to tackle the surgical mask shortage. Outer layer of mask is cotton woven fabric with water repellent cationic antiseptic coating. Middle layer is PTFE nano-fibres membrane. Inner layer is cotton lycra woven fabric. This design can prevent particles intake and spraying of bacteria while coughing by >99%. It can be repeatedly washed up to 30 times.