Touchscreens with copper coating kill germs

Touchscreens are some of the most contaminated surfaces that people touch everyday. However, copper’s antimicrobial qualities could change that.

Researchers from Spain’s Institute of Photonic Sciences (ICFO) and Corning Incorporated, an American multinational, have developed a transparent antimicrobial surface for touch displays using copper nanoparticles.

Copper is well known to be highly efficient in killing various microorganisms – and has been traditionally used for objects such as door handles and hospital bed rails. However, it is also opaque and electrically conductive, which makes it unsuitable for use on touchscreens.

With that in mind, researchers have designed “a transparent nanostructured copper surface (TANCS) that is non-conductive, and resistant against the growth of certain bacteria,” according to ICFO.

The researchers first deposited an ultra-thin copper film onto a glass substrate and then heated it to a very high temperature before cooling it down in a process called rapid thermal annealing.

This allowed the uniform film to “dewet” into individually distributed copper nanoparticles, resulting in “an antimicrobial effect, transparency, color neutrality, and electrician insulation,” the researchers said.

Layers of silicone dioxide and fluorosilanes were then added on top of the nanoparticles to provide environmental protection and durability.

Further tests, carried out under extremely dry conditions, showed TANCS eliminating over 99.9% of Staphylococcus Aureus bacteria present on the tested surfaces within two hours.

“While further development is necessary for full-fledged commercial deployment, this is a step in the right direction to enable antimicrobial touch screens for public or personal displays,” said Prantik Mazumder, researcher at Corning and co-author of the study.

The research was detailed in a paper published by the Communications Materials journal.