Lotusan® – dirt runs off with the rain
There is nowhere for facades to hide. They are exposed to emissions and weather conditions like the wind, day and night. Moisture caused by dew, fog and rain creates a breeding ground for algae and fungi. Over the years, dirt particles in the air settle on the facade causing an awful grey film. But Lotusan®, our intelligent facade paint, puts a stop to all that. We looked to the lotus plant for inspiration when developing its surface. It is covered with no end of tiny dimples that water simply runs off. Fine dirt particles are washed off with the water in this way, leaving the facade looking clean and pristine.
Would you like to find out more about biomimetics at Sto?
We would love to hear from you – whether you're an applicator, facility manager, building owner or maintenance manager!
We will be very happy to send you further details. Our test set gives you the chance to put our Dryonic Technology to the test for yourself.
Do you want to put biomimetics to the test for yourself? We will be very happy to send you further details and a test set for free.Find out our contact details here.
Lotusan® at a glance
Lotusan® facade paint is suitable for mineral and organic substrates. It is available in matt white and it can be applied using a paint brush, roller or airless spray.
At a glance:
- The tried-and-tested facade paint with Lotus-Effect® Technology for facades that stay clean for longer
- Maximum resistance to soiling
- Natural protection against algae and fungal attack
- Without biocidal film protection
- Structural weatherproofing not very important, therefore more design freedom
- Optionally available with heat shield against solar heating (X-black Technology)
- Lotusan® is also available in render form
Classes in accordance with EN 1062-1:
- Water vapour diffusion: V1 (high)
- Water permeability: W3 (low)
How our classic biomimetic technology, Lotusan®, works
We introduced our Lotusan® facade paint as our first-ever biomimetic product back in 1999. It is now referred to worldwide as a perfect example of a principle from the natural world being applied to technology. With its clever architecture made up of filler material, its microtexture mimics the surface of a lotus leaf. And so it offers an effective solution when it comes to one of the most important jobs of facades: water management. Dew, rain, and fog don’t have a chance to stick to the surface and instead they simply run off. Algae and fungi are deprived of the nutrients they need to grow, leaving the facade looking pristine.
“Are you proud, Mr Barthlott?” Three questions for the man who discovered the lotus effect
Professor Barthlott, how did you discover the lotus effect?
It happened back in the 70s when I was a young Biology doctoral student and research assistant at the University of Heidelberg. The first scanning electron microscopes had just been released. For me, that was fantastic because it meant that I could identify and systematise plant microstructures. I could see, for example, that cacti are related to carnations and so on.
So I would go and collect leaves from the greenhouses. If you want to get decent images using an electron microscope, the leaves have to be clean. That means no mud, dust, or crusty irrigation water residue. And that's when I noticed that I had to clean some of the leaves but not all of them. Yet they had all been next to one another in the same greenhouse.
This was down to their self-cleaning microtexture. You won a lot of prizes for this discovery. Why was it so well received?
Because it was completely unexpected. No other scientist before me had noticed the lotus effect. And that includes the biologists and the physicists, who just had a theory but no concrete surface or product. The commercial potential is huge given that what I discovered is so effective and relatively easy to apply to technical applications. Not to mention that it is relevant in terms of environmental concerns. A lot of toxic substances have now been replaced because surfaces have been made to mimic the lotus plant across a wide range of industrial fields.
Lotusan® facade paint has got to be the most well-know example. Are you proud of the success you have had in partnership with Sto?
Of course, I am still immensely proud of the discovery and development of Lotusan®. But what I am most happy about is the fact that Sto has been working on the principle of biomimetics and looks to nature for solutions. For example, Sto has used polar bear fur as the inspiration for active thermal insulation and taken the shell of the fog-basking beetle as the basis for another biomimetic facade paint.
Biomimetics. Our step ahead.
At Sto, we have been developing products based on the most efficient solutions from nature for 20 years. Our inspiration: 3430 million years of evolution – constant optimisation through further development. The benefit to you: radiant colour intensity, lasting UV and weather protection, facades that clean themselves, and a longer lifecycle for your buildings. We offer cost-effectiveness and ecology combined. This is what we mean by Building with conscience.
How a new generation of paints protects itself
Facade paints in our iQ – Intelligent Technology generation have special properties, with their surfaces protecting themselves against rain, soiling, fading, heat, and so much more. And there is no sign of biocidal film protection. Here at Sto, we have more than 160 employees working on environmentally friendly innovations like this in our Research and Development department. A whole three per cent of our turnover is allocated to this area.