Now you can grab that public bathroom door handle without fear—a solution to the conundrum of how to gracefully exit after washing your hands is finally here.

The two student inventors are among 20 finalists selected for the international James Dyson Award for their "illuminating" solution to bacteria-ridden doorhandles.

Despite the use of sanitizers and routine cleaning of public areas, the bathroom door handle presents a unique challenge. University of Hong Kong graduates Sum Ming Wong and Kin Pong Li set out to design a solution that was self-powered and avoided the chemical cleansers that are sometimes harmful to human health.

"Nowadays, people use chemical cleaning materials to clean up public areas, but it is both easy to wipe off and harmful to the human body," said the inventors. "Our design has high durability and [is] effective."

By using materials that cost only $13 per door handle, they combined titanium dioxide powder and ultraviolet LED lights to effectively develop a door handle that cleans itself.

Not only that, they also engineered a small gear box and generator to be hooked up to the door itself, making it self-powered. The kinetic energy generated from opening and closing the door provides enough electricity to keep the handle lit and functional.

The handle kills bacteria by the action of a thin titanium dioxide film on the outside of the clear handle. The chemical is known to be a photo-catalyst, so when the UV lights activate the coating, it reacts to water or oxygen to create hydroxyl radicals that decompose the bacteria. It killed 99.8% of bacteria in lab tests.