Sneakers Made Using Algae | Hacker News Reader

Sneakers Made Using Algae

smithsonianmag.com

45 pointspif7 comments

Having to get rid of toxins is a rather interesting problem to have when making plastic foam. Saxitoxin, a toxin produced by some algal blooms, is amazingly dangerous with LD50s of 5.7 μg/kg[0]. It's even been estimated that 50 μg of it absorbed through open wounds would be enough to kill a person.

All in all, this is probably a small issue. Potential barriers to scaling are that algal blooms form randomly, the need for solar drying, and whether the material actually holds up to use as well as the current foams we use. I'd even question that this is more sustainable than regular foam production until they do a full life cycle analysis of the process.

[0]https://en.wikipedia.org/wiki/Saxitoxin

Blooms don't form randomly, they form where excess phosphate and nitrogen accumulate. These are water soluble pollutants from agricultural and industrial sites so they follow the flow of the water table. When these nutrients meet open water algae populations that are already present increase proportionally to the increase in nutrient levels.

I agree that the business model hinges on the efficiency at which they can filter and remove water. The minimum concentration of algae per volume that they can profitably extract determines the areas available to harvest from. The article quotes one pair per 57 liters of water, which seems like the location they used must contain a pretty dense concentration of algae (>5 g/L of usable polymer).

Do you know if Saxitoxin decays with something like heating?

Very interesting. I wonder how they feel during sports. Alternatively these would be great as "sea shoes" that I often see with older people at the beach.

Relevant in the same area: https://www.dezeen.com/2015/07/08/adidas-parley-sports-shoe-... (Adidas reveals first shoe made out of recycled ocean waste)

This would be amazing if a fashion for recycled clothing drove a market for reclaimed polymers from the sea.

Re: sports, I note the company's website https://www.vivobarefoot.com/ lists a number of sports shoes, suggesting they have some experience of this area.

I'm not a vegetarian, but sometimes I feel pretty un-evolved walking around dressed in animal hides!

There are so many uses for polymer foam, I think this has amazing potential. Maybe it doesn't work out in energy terms, but it is a great idea to try

honest question, why are you wearing hides? I think I am wearing mostly vegetables (linen, cotton, hemp) and plastic/rubber, and I didn't even try to avoid fur/leather/wool.

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