This technique will initially be used to create antibacterial surfaces for use in the food production industry where it will increase productivity and reduce costs in factories which process biological food products.
TresClean has used high-power laser cutting devices to create a specifically tailored, rough micro-topography on sheet metal that mimics the surface of the Lotus leaf. This roughened surface creates miniature pockets of air that minimises the contact area between the surface and a liquid, causing the liquid to form spherical droplets that slide off.
Professor Luca Romoli, project coordinator of TresClean explained: “Bacteria do not get a chance to stick because the contact with the metal surface and the liquid is reduced by over 80%. We are looking at an anti-bacterial metal.”
While this replicating approach may currently exist for specific and expensive plastic components, it is a first for self-cleaning metal.
The researchers texture the metal surfaces using industrial photonics devices: high-average power ultrashort-pulsed lasers are used in combination with high-performance scanning heads by utilising an innovative beam delivery method enabling movements of up to 200m/s.
TresClean can achieve this surface texturation on areas of 500cm2 in less than 30 minutes, 156 times quicker than in early 2015. Then, production methods could make laser-etched metal at a rate of 1 square inch in 1 hour.
Prof Romoli sees the long-term possibilities and implications for sectors outside the food industry: “It is possible that any use of metal that needs to avoid the formation of bacteria will benefit from the TresClean product, such as medical cutting tools, sterile surfaces, dishwashers, or even saucepans.”