Fragility is a common problem in surface treatments, sometimes called "nanotechnology". There are super hydrophobic surface treatments that are very effective. They generate a surface which is a forest of tiny sharp points. The surface tension of water is too high to cling to such a surface. You can make something that just will not get wet. The problem is that the points are fragile, and wear destroys the effect.

Another example is ultra black coatings. Those are a forest of tiny black objects arranged so that light gets reflected multiple times and is absorbed. The commercial version is called "Vantablack". It doesn't wear well, but for optical applications such as the insides of camera lenses and telescopes, that's fine.

It's such a good book! Like any dad reading history, I have been annoying my family for years with fun facts I learned in that book. David McCullough's other books like The Great Bridge (about building the Brooklyn Bridge) are also great.

This is similar to a MIT press release from 2023.[1] That's another passive solar powered desalinization system that supposedly doesn't clog with salt. The author's paper list has the 2023 paper, but no followup.[2]

Another MIT paper on desalination from 2024 has a more conventional electrically powered system that can adjust its operating speed depending on how much power is coming in. So it can run off intermittent power sources such as its own solar panels.[3] Rather than buffering the energy with batteries, just buffer the water in a tank. This made it to field test and has some efficiency numbers.

It's annoying to see these one-off announcements with no followup. A short note a year later reporting why there's no further work would be useful to later workers.

[1] https://news.mit.edu/2023/desalination-system-could-produce-...

[2] https://drl.mit.edu/publications/journal/

[3] https://www.greenmemag.com/science-technology/breakthrough-m...

The crucial part is that pressure from the capillary action pushes the concentrated brine out onto the non capillary area. unlike fabric the area isn't enclosed so cleaning is easier if the salt starts to accumulate.

Obviously it needs to be cleaned regularly otherwise the salt encroaches into the sensitive bits. However the cleaning method doesn't require dissolving, just scraping.