In Development: New Laser System Creates Grease-Repellent Metal Surfaces

The end of scrubbing ovens and home appliances with chemicals or heat could soon be in sight, thanks to a new high-power laser system being developed to put ‘self-cleaning,’ grease-repellent and antibacterial properties into sheet metal. Teaming up with appliance giant Bosch, the European photonics consortium behind the laser system could soon see its technology create fluid-repellent surfaces fitted inside the next generation of dishwashers or refrigerators.

Coordinated in Germany by the Technical University Dresden, the LAMpAS consortium (“high throughput Laser structuring with Multiscale Periodic feature sizes for Advanced Surface Functionalities”) has received a grant of over $6 million from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 825132 – an initiative of the Photonics Public Private Partnership.

LAMpAS includes members from many European organizations including Next Scan Technology BV, Laser Engineering Applications SA (Belgium); Trumpf Laser GMBH, Robert Bosch GMBH (Germany); the European Photonics Industry Consortium (France); and BSH Electrodomesticos Espana SA, and New Infrared Technologies SL (Spain).

Preventing water, dirt or grease from ever attaching to the treated metal will keep appliances clean for a longer period without using detergents or heat.

Textured by some of the most powerful lasers in the world, this new laser-treated metal will have microscopic spikes or ridges that act like a bed of nails and stop dirt or liquids attaching themselves, as shown in the video below.

The laser creates an amphiphobic (repellent to water and oils) surface upon the metal similar to the defense mechanisms found in nature like Lotus leaves or springtails’ skin, enabling water and oil to simply roll off. Similar micro-nanostructures reduce the build-up of bacteria, meaning a surface never becomes dirty.

Although this work is currently being carried out on metal, the scientists say the laser-structuring technique works with other materials such as plastic and glass.

Some surface coatings like Teflon that make products easy to clean come with a serious downside: Toxic particles or gases can be emitted if the covering breaks apart.

The direct laser treatment of the surface – what the team calls “surface functionalization” or a way of altering the properties of the surface – provides an environmentally friendly and much safer alternative.

Teaming up with home appliance giant Bosch, the LAMpAS consortium is tailoring sheet metal to several different applications.

“We are targeting related use cases: medical surfaces in hospitals, like stainless steel antibacterial surfaces; packaging machines in the pharma industry that need to be disinfected; machines in the food processing sector that need be continually cleaned and where hygiene is paramount,” said, Dr Andrés Fabian Lasagni, LAMpAS project coordinator.

Grease-Repellent

While sheet metal has previously been textured to repel water and bacteria, preventing fingerprints remains a novel approach for laser-treated metal. Carved specifically to repel grease and fat, the metal will have the ability to repel water and oil simultaneously.

“We are treating sheet metal to obtain what we at LAMpAS call ‘anti-fingerprint’ characteristics. If we use this metal on the outside of a refrigerator, an oven or kitchen surface, the user would not have to clean finger or hand marks so often – meaning your fridge always stays shiny,” said Dr. Francesca Moglia, the laser technology leader in the European Photonics Industry Consortium (EPIC).

“The treatment of surfaces with special laser radiation and beam transport systems to improve their antibacterial properties opens up new frontiers in applications,” she added. “LAMpAS is using high-power ultrashort-pulsed lasers to create a rough micro-topography on sheet metal that will cause liquids to glide across the surface, thus, reducing the formation of a biofilm.”

Micro Structuring with Photonics

The team is working on producing self-cleaning metal sheets on an industrial scale. The metal surfaces are textured using industrial photonics devices: high-power, ultrashort-pulsed lasers are used in combination with high-performance scanning heads by utilizing an innovative beam delivery method that enables movements of up to 100 m/s.

“The idea of using photonics or high-powered lasers to create tiny structures on metal is nothing new but has always been too expensive to produce and too time-consuming,” said Lasagni. “Our laser system will allow us to treat more than 1 square meter of sheet metal per minute covering a potentially growing market that could reach nine-digit revenues per year in the home-appliance sector alone. With our innovative Direct Laser Interference Patterning (DLIP) Polygon Scanner head we will be able to treat metal with a 1.5 kW novel ps-laser source, with scanning speeds over 100 m/s.”