Laser Etching Could Make Metal Surfaces Kill Bacteria Instantly, New Study Says

Researchers have developed a laser treatment technique able to transform metal surfaces and allow them to instantly kill bacteria on contact.

Scientists at Purdue University announced on Thursday that they had developed a method to create tiny textures onto the surface of copper, giving the metal the ability to immediately kill dangerous bacteria including the antibiotic-resistant MRSA. The research was performed at Purdue's Birck Nanotechnology Center and was originally published in the journal Advanced Materials Interfaces in February.

"Copper has been used as an antimicrobial material for centuries. But it typically takes hours for native copper surfaces to kill off bacteria," Purdue University assistant professor of materials engineering Rahim Rahimi said in a press release. "We developed a one-step laser-texturing technique that effectively enhances the bacteria-killing properties of copper's surface."

Textures were etched into the surfaces of the metal with lasers, increasing overall surface area and causing the bacteria to make direct contact with the surface, which then killed the pathogens instantly.

Researchers believe the treatment could be easily applied to improve medical implants like hip or knee replacements, giving the implants the ability to more easily bind with the body's bone cells. The technique has also been applied to material other than copper, including materials that may be used in wound dressings.

textured samples
Copper and titanium metal samples that have been treated to modify texture on the right sides only are displayed with water on both the modified and unmodified sides. Purdue University photos/Erin Easterling

Bacteria that have become resistant to antibiotics would be defenseless against the modified surfaces. Coating doorknobs and other surfaces, especially in settings like hospitals, could help greatly reduce new infections.

"Antibiotic resistance is a big challenge right now, there are superbugs and bugs that are becoming more aggressive, antibiotics are not effective on them," said Rahimi. "We're developing technology that allows us to modify the surface of metal by laser surface modification to enhance antimicrobial properties."

Unlike other treatments that have attempted to enhance the antimicrobial properties of metal by coating surfaces, the new process has the advantage of enhancing the properties of metal without adding anything.

"The nice thing about our approach is it's not something [we are] adding to the surface, so there's no kind of additional material required, no antibiotics, no spray coating," Rahimi said. "It's just modifying the native surface of the material."

The scientists cautioned that the current technique would not be effective against viruses, including the one responsible for the current COVID-19 pandemic. Bacteria are far larger than viruses and it is unclear whether the treatment could be successfully adapted to work against pathogens as small a virus.

Newsweek reached out to Rahimi for additional comment but did not receive a response in time for publication.