If you find it depressing that you can’t see who’s smiling, who’s being friendly or who’s pretty or handsome because of masks, hope has come from the University of Science and Technology at Clear Water Bay. Soon, if industry gets behind the UST’s new discovery, we may all be wearing transparent, breathable masks.

Professor Gao Ping of the Chemical and Biological Engineering Department has announced development of a new ultrathin, transparent nanofilm suitable for face masks. The film can filter out 99 per cent of viruses, bacteria or particulates. It’s “the world’s strongest polymer nanomembrane 25 times stronger than steel of the same mass”, Prof. Gao says. It’s gas-permeable and water-proof and has many applications especially medical but also in desalination, electronics and solar cells.

“This novel material has much potential but since the pandemic struck, we have focused on turning our nanofilm into a face mask that is not only transparent and breathable, but is also highly efficient against viruses and bacteria, as we haven’t seen one in the market which bears all these properties,” Prof. Gao said. “While common opaque surgical masks can protect the wearer from infection, they are not convenient for hearing-impaired people who need to communicate via lipreading and facial language, or teacher, child carers or performers who rely heavily on facial expressions. . .”

The new nanofilm has wide applications notably medical. “It’s conformity, antibacterial, transparent, yet strong properties make it ideal for many medical purposes such as wound dressing. It is especially good for burn victims, becoming a new skin through which doctors can apply medicines.”


The nanofilm is one-thousandth the thickness of a human hair and is made from ultra-high-molecular-weight polyethylene, used in bullet proof vests.