HONG KONG, Dec. 21 (Xinhua) -- The Hong Kong University of Science and Technology (HKUST) said on Monday that they have developed an ultrathin polymer nanofilm and produced a prototype face mask with a 99-percent filtration efficiency for virus, bacteria and particulate matters.

The polymer nanomembrane is not only 25 times stronger than stainless steel with the same mass, but is also extremely transparent, gas-permeable and water-proof with adjustable porous properties, making it suitable for use as wearable devices, medical protection, desalination, electronics, solar cells and many other cutting-edge technologies, according to the university.

Gao Ping, professor of Chemical and Biological Engineering and acting head of the Advanced Materials Thrust at HKUST (GZ), said that while common opaque surgical masks can protect the wearer from infection, they are not convenient for the hearing-impaired people who need to communicate via lip reading and facial language, or teachers, child carers of performers who rely heavily on facial expressions.

"This novel material has many potential, but since the pandemic struck, we focus on turning our nanofilm into a face mask that is not only transparent and breathable, but is also highly efficient against virus and bacteria, as we haven't yet seen one in the market which bears all three properties," Gao said.

The material's conformity, antibacterial, transparent yet strong properties has also made it an ideal material for various biomedical causes, including a new generation of wound dressing which require no daily replacement and allows direct application of medicine.

"Wound dressing made with this nanofilm is particularly useful for patients who suffer large-scale burns," Gao said, adding that it acts like a temporary skin to the burn victim and as the film is completely water-proof, wearers can even take a shower without fearing of wetting the wound.

Apart from biomedical and environmental use, the nanofilm can also be applied to electrical appliances, such as nanovibrational speaker with higher resolution of audio output or ultrathin batteries and high-energy density capacitors, according to the university.