Growing leather using bacteria instead of cows
  • So this is a project we've been working on over at Scihouse for a while now. Leather is inherently bad for the environment, both because of the tanning process that's used in most of the world, and because of the source of the starting material (cows). So we've been workin on growin a leather like material that is extremely strong from bacteria. Specifically, Kombucha. Kombucha is a fermented tea beverage that's fizzy and I find it really tasty. Part of it's life cycle is it grows a thick layer of polymers on the surface of the liquid as it grows. This slimy sheet is normally just thrown out, but with a few very simple treatments, it's really easy to turn it into a material that looks and feels just like real leather. Check out our first video on how to do it:

    LINK
  • Somebody shared it on facebook.

    I'm just wondering how long has this technique / technology been around? Because I recall someone mentioning "hope that one day this gets less costly" and they were saying "on a mass production context". I was about to say that "if this is new then there needs time to develop means of mass production, no matter how cheap."
  • Very interesting. Reading the comments on Youtube, seems like it's pretty tough stuff if you can't find anyone to tear it, but from the video it looks flimsy as anything and very thin. I'm sure you'll be at the forefront of a new fashion craze if you can get clear faux leather wallets to take off.
  • the stuff seems really interesting. Altho you couldn't sell me on building clear wallets from it. That'd be like a pickpocket's wet dream come true.
  • I'll admit, I didn't even think about security issues regarding a clear wallet... but I'm certain if you stuck it on a popular celebrity it would sell like hotcakes. Might even  dope them with something luminescent for bonus points!
  • yeah, celebriti worn, clear, vegan, led-lit, bluetooth-locate-token wallet. you can probably bump a kickstarter campain into 7 digit values or more.
  • Fascinating stuff. I find myself immediately wondering at armor applications, such as for motorcycling gear or other safety equipment. Tensile strength, sheer strength, and abrasion resistance would be interesting things to see compared to actual leather. Flexibility of particularly thick samples of the material would be interesting to know more about. I wonder if you could embed other materials into this faux leather during the growth of SCOBY for interesting results, Kevlar or various fiber materials come to mind.
  • mass producing this should be really easy, and we're already working on scaling. If it works, it should be really cheap to do.

    Ha, ya. Making a nice raincoat and having a celeb show it off woud certainly draw a crowd.


  • theoretically speaking it should be possible to grow the material in the precise shape required by the later application by using a specially formed tray. Which would entirely eliminate any cut away material or waste of resources. Although that would make processing a bit more difficult, still an interesting aspect.
  • Definitely an interesting idea here! Having tons of SCOBYs in a couple jars from making kombucha here at home I may have to give this a spin. I'm a bit of a primitive living/colonial pioneer era nerd so I own tons of leather equipment of various design and want to see how it stacks up against the real thing.

    I feel like there are some ideas in my brain concerning kombucha stacked into a "laminate" and other methods of combining different grades of the "kombucha leather" but I'll have to make my own and see what it's like before the ideas get too carried away. In particular, I'm attracted to how transparent the material can be and novel ways to create decorative leather in a way you just can't do with the real deal.

    Edit: http://www.instructables.com/id/Kombucha-Fabric/
  • Trying this as sooon as i find a friend with a Scoby.
    As one wo follows a vegan diet and fucking *loves* leather this falls right in that Venn sweet spot. :3
  • Interesting. I got a new one in days before grindfest. I'm going to fill up like 5 different five gallon jugs. I'll send you a scoby when it's mature helyx
  • I tried something like this previously and if I remember correctly it actually ends up hard and brittle, no?
  • Nope. so far it's only gotten better with time. thus far our process is working extremely well at preserving the finished material
  • My gut tells me it's not, but I've got to ask. Do you think it is/could be made biocompatible? I know it'd probably be a nightmare to sterilize.
  • Question: does this need constant application of the oils to maintain the softness and ductility?
  • Actually that's something we're exploring. Decellularizing it and using it as a scaffold for tissue culture.

    With our recipe it doesn't seem to, but we'll see how it holds up over time
  • It'd be interesting to see how it holds up with a Young's modulus test. I doubt it's as strong as actual leather but I'm sure it's far stronger then faux leather crap. It'd probably be fine for something like motorcycle gear. If it is comparable to leather, then the fact you can grow items without a seam is interesting.
  • It needs to be grown on top of liquid though. I can't really see how we can grow something like a pocket for example.

    Edit: wait, if I stick something into the tea will SCOBY grow all around the bit that is in the tea?
  • I bet if you took your culture liquid, mixed it with gelatin, and let it set up, you could probably grow your scoby culture in a shape. @IvoTheSquire no it wouldn't. Scoby's an aerobic culture, so you'd just get a culture with a hole in it. 
  • @chironex how would you be able to use it as a tissue culture. Once you decellularize it wouldn't the polymers make it close to plastic? Wait... I guess you could just grow new bacteria and yeast in it.
  • It only really compacts when it's dried. When it's fresh it can be decellularized without collapsing the structure. You'd just need to grow your layer to the thickness you want, decell it, clean it and then seed it with new cells. 
  • A friend took it to a lab and tested the ultimate tensile strength, just for a lark. It's at around 40-60 MPa. That puts the strength at around nylon levels, maybe a bit higher.
  • Do you have access to a weathering tank? I'm curious how durable the treated material will be.
  • @glims: Looks comparable with the real thing:

    http://textile.webhost.uoradea.ro/Annals/Vol%20XV-no%20I/Art.%20nr.%2029,%20pag%20157-162.pdf
  • CassoxCassox May 12
    So there are a lot of potential projects related to this. I think you could eliminate seams by taking two pieces and putting it back in the bath. New growth would bond the pieces together allowing for larger sheets and sizes.

    Also, now about using it like a semipermiable membrane? If you grew it around a piece of mesh fabric, you could easily suspend it. If you had a container and used one as a kind of false bottom, I bet it'd make a great filter. How effective? Idk.. but wouldn't it be amazing if you could remove salts and particles from sea water? I don't think it'd work but it would certainly function to remove particles like a prefilter.. and it's obviously cheap to make and biodegradable.
    I like the idea of using it to grow plants. I think hydrogen peroxide at a low concentration could kill off the organisms. You could give it a good flush and then put seeds inside.
    Lots of fun stuff.