Researchers at Flinders University have developed an electrically activated antibacterial coating that uses microscopic cracks in its surface to help kill dangerous bacteria, including antibiotic-resistant strains.
The flexible material combines liquid gallium, a metal that melts at room temperature, with carbon nanotubes. As the coating dries, tiny cracks naturally form on the surface. Instead of weakening the material, these networks create electrical hotspots that enhance its antibacterial activity.
In laboratory tests, a minute of electrical stimulation with a standard 9-volt battery killed more than 80% of bacterial cells within three hours, according to the researchers.
The results could eventually lead to smart wound dressings, flexible medical devices and wearable technologies that help prevent infections without relying solely on antibiotics.
Cracks create electrical hotspots
The international research team, led by scientists from Flinders University’s Biomedical Nanoengineering Laboratory, developed the coating to produce an antibacterial response when activated by a small electrical charge.
As the mixture of liquid gallium and carbon nanotubes dried, microscopic cracks naturally formed on the surface. The researchers found that these structures concentrated electrical activity in tiny hotspots, helping to amplify the material’s ability to damage bacterial cells.
The electrical stimulation increased stress within the bacteria and contributed to cell damage and death. The coating could also generate plasma, an energetic gas that produces reactive molecules known to suppress bacterial growth.
This combination of electrical and plasma effects gives the material its antibacterial properties. The researchers say the cracks can be specifically incorporated into the coating and not treated as unwanted defects.
Associate Professor Vi-Khanh Truong, from Flinders University’s College of Medicine and Public Health and the Flinders Health and Medical Research Institute, said the findings challenged traditional engineering approaches.
“Instead of viewing cracks as defects, we showed that they can be transformed into materials to create useful functions,” Truong said.
Testing against resistant bacteria
The researchers tested the coating against methicillin resistance Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Both bacteria can cause serious infections, particularly in healthcare settings and vulnerable patients.
After just one minute of electrical stimulation, more than 80% of the bacterial cells had died within three hours. Laboratory tests also showed that the material remained compatible with human skin cells under the conditions tested.
The results suggest that the coating could eventually be integrated into flexible medical devices that exert an antibacterial effect directly at the site of infection.
Potential applications include wound dressings to help protect difficult-to-heal injuries and wearable patches that combine infection prevention with health monitoring. The material can bend, stretch and conduct electricity, making it potentially suitable for soft, skin-mounted devices and smart textiles.
Such systems could one day monitor signals such as heart or muscle activity while providing additional protection against bacterial growth.
However, the technology is still at an early stage of research. Laboratory results do not demonstrate safety or effectiveness in patients and further testing is required before it can be considered for medical use.
The research was published in the journal Small structures.
