Anish Tutja, a professor of materials science and engineering at the University of Michigan, said the coating could be a game-changer in public places such as airports and hospitals that are traditionally full of bacteria. “We’ve never had a good way to keep frequently touched surfaces like airport touchscreens clean. Sanitizers kill germs in a minute or two, but they dissipate quickly, leaving the surface vulnerable to recontamination. And the new coating provides The best of both worlds solution.”

This clear coat can be brushed or sprayed for durability and germicidal power. It uses antibacterial molecules extracted from tea tree oil and cinnamon oil. Both oils have been used for hundreds of years as safe and effective fungicides that work within two minutes. The durability of the coating comes from polyurethane, a tough, varnish-like sealant commonly used on surfaces like floors and furniture.

Durability test results showed that the coating continued to kill bacteria for at least 6 months before its oil began to evaporate and reduce its ability to disinfect. After wiping with new oil, it can be re-provided for a new round of protection.

The key challenge of the new technology is to combine the oil and the polyurethane, allowing the oil molecules to exert their germicidal effect while preventing them from evaporating quickly. The research team discovered a solution for cross-linking, which links materials together at the molecular level through heat. Smaller oil molecules readily combine with cross-linked polymer molecules to form a stable matrix.

The researchers then set out to find a combination of active ingredients that would kill a variety of the bacteria that most plague humans. Ultimately, they discovered the precise balance of effective, safe, and inexpensive antimicrobial molecules. The researchers stress that the formulations are not set in stone and can be adjusted for specific applications or rebalanced antimicrobials to kill specific bacteria.