TresClean’s Lotus Leaf Inspired Self-cleaning Metal Promises Immediate Application in Milk Processing

Tresclean Project with its breakthrough innovation has invented a self-cleaning sheet metal for the first time on an industrial scale. The technology was inspired by defense mechanism present in lotus leaf which cleans itself of bacteria. A lotus leaf is super hydrophobic. The nanostructures on a lotus leaf are coated with hydrophobic wax which protects the leaf from accumulating dirt, often called as Lotus Effect. Researcher’s working on the TresClean project, have created a similar metal surface with an ability to self-clean itself.

TresClean which stands for ‘High Throughput Laser Texturing of Self-Cleaning and Antibacterial Surfaces’ has used high-powered laser cutting devices to create microscopic ridges and spikes on a sheet metal. The resultant surface with its micro-topographical roughness bounces off any liquid from the surface mimicking the lotus effect. The surface manages this ‘bounce off effect’ by creating miniature air pockets on the surface which minimizes the area of contact between the liquid and the surface. The liquid if observed from a microscopic level would look more like sitting on a bed of needles.

The metal surface will be used initially in food production industry where biological food products have to be processed on a large scale like tomato sauce, milk and yogurt. Generally in the factories, food processing vats in milk factories have to be changed or cleaned after every 6-8 hours to avoid bacterial activity from surging exponentially which may cause food spoilage leading to wastage. The new metal surface if used in these factories will increase efficiency and reduce time. Fewer sterilization cycles along with minimized cleaning time will improve productivity and reduce energy consumption making the process safer, quicker and profitable.

The metal will achieve this by reducing the contact between the bacteria and the surface by as good as 80%. The technology based on lotus effect will ensure that liquid droplets remain spherical avoiding it to spread over the surface.

Although such an effect has already been tested on certain plastics; however large scale industrial applications for a sheet metal is something new in the industry. Photonics devices have been traditionally used to texture metal surfaces using high-powered ultra-short pulses along with scanning heads which enables movements at 200m/s but TresClean can achieve this by cutting 500 Sq. cm in less than half an hour. In 2015 some methods could manage a rate of 1 Sq. inch/ hour of laser etched metal production but TresClean’s newest technology is 156 times more efficient and quick promising to produce 1000 Sq. cm in the same amount of time. This will pave the way for large scale industrial application of the technology.

Project coordinator of TresClean Professor Luca Romoli, is extremely confident about the future applications of the technique in several industries where bacterial contamination is a major problem. Potential use of the metal includes medical cutting tools, dishwashers, saucepans and sterile surfaces.