[HN Gopher] Kombucha cultures can be turned into flexible electr...
       ___________________________________________________________________
        
       Kombucha cultures can be turned into flexible electric circuit
       boards
        
       Author : thedday
       Score  : 112 points
       Date   : 2023-02-23 02:40 UTC (1 days ago)
        
 (HTM) web link (arstechnica.com)
 (TXT) w3m dump (arstechnica.com)
        
       | LBJsPNS wrote:
       | Well it's nice to see someone has turned that disgusting mildewy
       | crap into something useful.
        
         | niccl wrote:
         | A friend of mine dries it with some fruit extract and makes a
         | really good fruit leather. Not sure of the details, but I am
         | sure it tastes great
        
       | sva_ wrote:
       | I'm always fascinated that most cultures have some fermented
       | foods in their cuisine. I often wonder how they came up with it.
       | Extreme thirst or hunger? Curiosity? Or have they slowly
       | 'evolved' in a way that people let them ferment more and more
       | over time?!
        
         | messe wrote:
         | If you leave something around long enough, it often ferments.
         | 
         | Sometimes the result smells ok.
         | 
         | Eventually somebody is curious enough to try it.
        
           | ilyt wrote:
           | > Eventually somebody is curious enough to try it.
           | 
           | Or "just" hungry enough
        
       | wackycat wrote:
       | I feel like I often see breakthroughs in natural material
       | computing like this but they never seem to make it to market that
       | I've noticed. What am I missing? It seems like everyone would
       | want to move in the direction of sustainable computing materials.
        
         | 1270018080 wrote:
         | It's probably always cost and scale
        
       | snek_case wrote:
       | But, is Kombucha Turing-complete?
        
       | poulsbohemian wrote:
       | I have a bunch of weird hobbies, including things like brewing
       | mead, making cheese, and yes, I have made kombucha. Years ago
       | when they were still in a garage, I walked into the "office" of
       | what is now a nationwide kombucha brand. I didn't know anything
       | about kombucha but there was a lot of hype about these people. I
       | started asking questions and was directed to the "head brewer." I
       | wanted to talk microbiology, but it was very evident they had no
       | effing clue what was actually in their mother culture. Sure, they
       | knew how to dump it into their tea, but that was about it. Not
       | very long after that, they had reached national distribution. I
       | think there are a lot of lessons in there for people who are
       | worried about imposter syndrome or people who think all you do is
       | build a better mousetrap, as it had nothing to do with their
       | product and everything to do with the founder having deep ties to
       | the grocery world.
        
         | htag wrote:
         | A non-technical cofounder with deep industry ties is a strong
         | positive signal.
        
           | poulsbohemian wrote:
           | Absolutely - as far as I know, they had just one founder, who
           | was very clearly a sales / marketing type. My guess is that
           | they didn't really have any passion for kombucha (I only met
           | them once, by accident really, so don't know the story...)
           | but had done the research on a product that was primed for
           | commercialization.
        
         | eat_veggies wrote:
         | When it comes to fermentation, you can get pretty far by
         | developing a good intuition (through experience) of how to
         | steward your little ecosystem and how it responds to your
         | particular ingredients and environment. You can be an expert on
         | that and produce great flavors without knowing the
         | microbiology, like cheesemakers and brewers have done for
         | thousands of years.
         | 
         | Granted, the hard science is helpful in getting to the next
         | level and achieving a product that's consistent from batch to
         | batch.
        
           | poulsbohemian wrote:
           | >Granted, the hard science is helpful in getting to the next
           | level and achieving a product that's consistent from batch to
           | batch.
           | 
           | That was the part that was eye opening. It's one thing if I'm
           | making something in my kitchen for my use, it's another when
           | you have already achieved regional distribution of a product
           | but clearly have no idea what's actually in it.
        
       | causi wrote:
       | I don't get why this is significant. How is this a better
       | substrate than any other flexible plastic? Isn't the issue with
       | flexible electronics the robustness of the circuits and
       | components?
        
         | jagermo wrote:
         | according to Ars Technica, its lighter, cheaper and more
         | flexible. and probably degrades faster.
         | https://arstechnica.com/science/2023/02/kombucha-electronics...
        
           | [deleted]
        
           | blarghyblarg wrote:
           | It consumes sugar and creates carbon dioxide. I know this
           | might seem facetious, but I'm actually curious... are the
           | greenhouse emissions lower?
        
             | inkcapmushroom wrote:
             | SCOBY is basically a waste product from producing kombucha,
             | you have to remove an amount from each batch which (in the
             | case of home brewing) is usually given away to others for
             | free or discarded, not sure how they handle it with
             | industrial-scale kombucha making. So this could be more of
             | a clever recycling that doesn't produce any more CO2 than
             | was already being produced during the making of kombucha.
        
             | pokot0 wrote:
             | No, it's a good point and I'd like to know as well. Ofc
             | being biodegradable means it will sooner find it's way into
             | some photosynthesis and recapture that carbon.
        
               | causi wrote:
               | To be fair, the carbon content of a conventional circuit
               | board is already sequestered in the circuit board.
        
             | NickBusey wrote:
             | Are greenhouse emissions lower when fermenting some sweet
             | tea, versus extracting oil from the earth, refining it,
             | converting that into plastic, then forming that plastic
             | into the shape you want?
             | 
             | I'm going to go out on a limb here and say, yes.
        
             | TSiege wrote:
             | This is true if you make naive assumptions like making
             | circuit boards are a clean technology with no CO2 emissions
             | or other harmful side effects. That of course is entirely
             | incorrect. Printing circuit boards are very energy
             | intensive along with a lot of other impacts like toxic
             | waste and heavy water use.
             | 
             | > In the US, a single fab, Intel's 700-acre campus in
             | Ocotillo, Arizona, produced nearly 15,000 tons of waste in
             | the first three months of this year, about 60% of it
             | hazardous. It also consumed 927m gallons of fresh water,
             | enough to fill about 1,400 Olympic swimming pools, and used
             | 561m kilowatt-hours of energy. (source https://www.theguard
             | ian.com/environment/2021/sep/18/semicond...)
             | 
             | Kombucha on the other hand, yes produces CO2 as a waste
             | product, but it is very easy to see a kombucha SCOBY being
             | carbon neutral. That is the source of it's sugars being
             | carbon energy free, and the manufacturing process of SCOBY
             | circuits as well. Then it's carbon neutral
        
               | grogenaut wrote:
               | Is that Intel fab doing circuit boards or etching silicon
               | wafers for integrated circuits, a completely different
               | operation.
               | 
               | Doing a CPU out of a scoby would be real bio computing :)
        
           | mouse_ wrote:
           | I can turn a piece of cheese into a flexible circuit board,
           | if anyone wants to give me venture capital for that...
        
             | carapace wrote:
             | You might be joking, but you can actually make plastic out
             | of milk/cheese: https://en.wikipedia.org/wiki/Casein
        
               | LBJsPNS wrote:
               | So you've had Kraft singles, I see.
        
         | Maxion wrote:
         | Article was paywalled for me, but in general Plastic does not
         | decay so for products that are essentially consumables it's
         | better if it doesn't stay and pollute the environment.
        
         | fit2rule wrote:
         | [dead]
        
         | ascotan wrote:
         | People have been working on bio circuitry for decades now. Not
         | sure of it's utility but man-machine interface comes to mind. I
         | think the fact that it's biodegradable is probably not the
         | point.
        
         | ajsnigrutin wrote:
         | Environmentally speaking, it's better, since it's
         | biodegradable.
         | 
         | On the other hand, buying a gadget that dissolves when it gets
         | just a bit wet might not be a smart thing...
         | 
         | But i can totally see them selling "biodegradable" flashing LED
         | bracelets (or similar single-use crap), where the bracelet
         | iself is biodegradable, and the rechargable battery (without an
         | actual charging circuit) and plastic potted LEDs are not....
        
           | stdbrouw wrote:
           | FWIW, it's biodegradable but it doesn't dissolve in water. If
           | you've never handled a kombucha scoby, it's very rubbery and
           | tough.
        
             | ajsnigrutin wrote:
             | I've held it, but i've also got it wet (after being dry),
             | and i seriously doubt that the printed-on metalic layer
             | would survive, since the surface gets soft and jelloey.
        
               | TSiege wrote:
               | A scoby is just basically a matrix of cellulose. Assuming
               | the circuits are printed into that substrate it could be
               | quite stable
        
           | dokem wrote:
           | Isn't biodegradability not a feature we want in most
           | manufactured goods? Doesn't that just mean they will start to
           | rot and break down on their own?
        
             | ajsnigrutin wrote:
             | Depends on what you want.
             | 
             | Disposable cups, plates, forks, spoons, etc? Sure... eat
             | whatever was in them, throw them wherever, and they'll rot
             | very fast.
             | 
             | Electronics.. mostly not. Maybe some light-up bracelets for
             | a festival, but those also contain batteries and LEDs, but
             | it's still better if at least the strap degrades and rot.
        
               | schwartzworld wrote:
               | Lots of electronics are waterproofed as well. I doubt
               | that biodegradation would happen very quickly inside a
               | modern smartphone chassis
        
             | teucris wrote:
             | The issue is time scales. Plastics take thousands of years
             | to degrade but we only really use plastic products for a
             | few years. What can we find that hits a sweet spot of, say,
             | 10 years? Wood does this well, and it's mostly cellulose.
             | So is paper and this stuff.
        
             | userbinator wrote:
             | It's not, but the planned obsolescence advocates sure love
             | it, since they can make products self-destruct and eco-
             | virtue-signal at the same time.
        
             | orthecreedence wrote:
             | If people are going to manufacture trash that breaks or
             | become oBsOlEtE after a year anyway, you might as well have
             | it biodegrade when it's done.
        
       | haskellandchill wrote:
       | Is there a cheaper way to make circuits? Those printers are
       | apparently in the $200k range?
        
       | dghughes wrote:
       | Kombucha tastes like a circuit board so making them into circuit
       | boards is a good idea.
        
         | kodah wrote:
         | I brew Kombucha. It's actually delicious, but you need to get a
         | batch made by someone who knows what they're doing.
         | Unfortunately, the latter is hard to come by because there's
         | very little science in Kombucha circles.
        
           | richeyryan wrote:
           | Ain't that the truth? So much folklore and superstition about
           | how the fermentation process works. I remember being told you
           | can't make Jun with a Kombucha starter because it's a
           | different bacteria, and even if you did get Kombucha to
           | ferment the honey, it wouldn't actually be Jun. And the
           | complete obsession and misinformation around the pellicle!
        
             | kodah wrote:
             | The pellicle stuff drives me nuts but I feel pedantic
             | correcting people. I need to find an easier way to observe
             | bacteria, because right now I'm relying on sugar content to
             | determine "doneness", which is pretty second order to all
             | the things that can happen around sugar in a kombucha brew.
        
         | Xeoncross wrote:
         | I laughed out-loud for that.
         | 
         | As someone that enjoys some (but not all) sodas and kombuchas I
         | really recommend people try several. Don't think all
         | wines/sodas/teas/smoothies etc... are the same. They can be
         | made from just about anything (fortunately/unfortunately)
        
           | Jeff_Brown wrote:
           | I hate beer and soda, but I've never met a kombucha I didn't
           | love.
        
             | qup wrote:
             | Do you think it's a texture thing? Or lack of varied
             | experience?
             | 
             | Those two products have tens of thousands of flavor
             | profiles, it's strange to me that you can dismiss them
             | entirely.
             | 
             | I had a red velvet cheesecake craft beer the other day and
             | there was no hint of "beer" in it.
             | 
             | I like everything, and I've never had kombucha, so this
             | thread has me excited to try it... Many times, for the
             | various flavors!
        
               | Jeff_Brown wrote:
               | I loved soda as a kid, and beer in my twenties. Now I
               | quite dislike the taste of alcohol and sugar in the
               | quantities one typically finds in beer and soda, but
               | you're right, there are exceptions I have enjoyed.
               | They've been rare. (I haven't kept track, and I haven't
               | actively sought them out either.)
        
         | deelowe wrote:
         | Whenever someone tells me how much they love kombucha, I get
         | the feeling they are trying to convince themselves more than
         | they are me.
        
           | cactusplant7374 wrote:
           | I genuinely love salty licorice. Sometimes we learn to love
           | gross things.
        
           | vbezhenar wrote:
           | When I brewed my kombucha, it was all about how much time do
           | you spend on brewing. In the start it's just very sweet black
           | tea. As time goes, sugar gets processed into acids. With a
           | lot of time, it turns into very acidic mix so it's definitely
           | not something to enjoy and probably not healthy for stomach.
           | So depending on how much time do you spend, you'll get
           | something in between which might be not very tasty or might
           | actually be very tasty.
           | 
           | You can also swap black tea for green tea or other liquids.
           | I'm think that kombucha does not care, all it needs is sugar
           | and tea is for human (although I might be wrong about it).
           | 
           | I actually liked it, but it requires too much housekeeping,
           | so I abandoned it.
        
           | badrabbit wrote:
           | Not true, i love it. Not always, kinda like beer there are
           | times when it is more tasty
        
           | klyrs wrote:
           | The best kombucha I ever had was like drinking vinegar. I
           | happen to love drinking vinegar, just as much as I love
           | drinking lemon juice. Only, that's horrible for one's teeth,
           | so I must restrain myself. I've had kombucha people tell me
           | that vinegar is disgusting and the kombucha I had was "off."
           | Oh well. To each their own.
        
             | badrabbit wrote:
             | I like kombucha but also lemon juice lol. You don't like
             | the taste of alcohol or coffee either at first but then you
             | love it
        
           | NickBusey wrote:
           | Whenever someone tells me how much they hate kombucha, I get
           | the feeling they tried one gross bottle one time, and wrote
           | it all off as bad.
           | 
           | I am brewing 5 flavors right now in my house. I assure you,
           | they are delicious.
           | 
           | Guava Jasmine is my current favorite.
           | 
           | But keep hating on it if you like, you're missing out on
           | something great.
        
             | brahyam wrote:
             | Could you share any good resources for someone to start
             | brewing it? Or any tips?
        
               | NickBusey wrote:
               | Make sweet tea, add SCOBY, wait. It really is that
               | simple.
               | 
               | This is the basic recipe I use: https://www.reddit.com/r/
               | kombucha/wiki/how_to_start#wiki_mas...
               | 
               | For more information, The Big Book of Kombucha will have
               | everything you need and more.
               | 
               | Have fun! :)
        
               | tlavoie wrote:
               | Now, how about limiting the fermentation after bottling?
               | I have a couple bottles still in the fridge, that I now
               | call "kombucha grenades." I thought I could open the last
               | one I tried safely, in the sink, and it basically hosed
               | the kitchen and myself. The last few will be outside-only
               | endeavours, wearing a garbage bag like a Gallagher
               | audience member. (Tastes good, at least the half a bottle
               | that is still in the bottle.)
        
               | NickBusey wrote:
               | Keep them in the fridge for longer, the carbonation will
               | go down over time.
               | 
               | Also, try placing the bottle in a container or bowl, then
               | hold another (slightly narrower container) over the top
               | of the bottle. You should be able to catch all of the
               | liquid in the bowl to pour into a glass.
               | 
               | If you added a bunch of sugar and/or flavoring into the
               | secondary fermentation / bottles, you added too much. If
               | you didn't add anything, then you didn't let the primary
               | fermentation go long enough.
        
               | tlavoie wrote:
               | Oh, guessing the latter, thanks! I hadn't added anything
               | for a secondary or bottling stage. I am used to regular
               | beer brewing, I think that runs out of steam sooner. Will
               | have to try the two-bowl method.
        
               | lcnPylGDnU4H9OF wrote:
               | > SCOBY (symbiotic culture of bacteria and yeast)
               | 
               | https://www.youbrewkombucha.com/scoby-care-hotel
               | 
               | (Just passing by; I have no personal interest in
               | kombucha, was simply unaware of the term.)
        
             | not_a_shill wrote:
             | There are people out there that feel the same way about
             | eating rats
        
             | folkrav wrote:
             | Yeah. I don't know my kombucha like you seem to, but I've
             | just tried two flavors by two separate brands recently. One
             | (I can't remember what it was) was barely drinkable, second
             | one (hibiscus & rose hips by RISE kombucha) was delicious.
             | It's weird to me to somehow being able to write off a whole
             | family of drinks as undrinkable. I don't like purple Crush,
             | doesn't mean I don't like all colas. I don't like Bombay
             | Sapphire, but gin can be delicious. And so on...
        
               | schwartzworld wrote:
               | Homemade tends to be milder than store bought and less
               | vinegary. It continues to ferment as it sits on store
               | shelves.
        
             | Insanity wrote:
             | I love Guava but have not tried it as kombucha yet,
             | definitely should give that a try! My personal favourite is
             | either "ginger" or Canadian Berry
             | (https://www.farmboy.ca/products/farm-boy-organic-canadian-
             | be...). _Very_ different flavour, but could drink those all
             | the time.
        
           | lepus wrote:
           | Shhh, let people enjoy things.
        
           | Insanity wrote:
           | It depends, I genuinely like Kombucha. But it's not a blanket
           | statement for all of them, there's many different flavours
           | and some I dislike, some I like. :)
        
           | SpaceL10n wrote:
           | For me, kombucha has been a natural progression of my
           | exploration into fermented foods. The concept that so many of
           | our favorite foods are produced with the assistance of
           | bacteria is just fascinating to me. The funky flavors of
           | fermented foods is a hurdle, for sure.
        
           | junon wrote:
           | Whenever someone asserts subjective opinion as some sort of
           | axiom I dismiss them and their comment entirely.
           | 
           | See how that works?
        
         | pokot0 wrote:
         | I love Kombucha but hate 99% of those you find in stores. They
         | do taste like a circuit board.
        
           | lapetitejort wrote:
           | Store brands are weak, pasteurized, and filtered, such that
           | any unique flavor has been removed to appeal to the average
           | shopper. Drink someone's home-brewed kombucha and you will be
           | blessed with flavors that cannot be found anywhere else.
           | 
           | This goes for all fermented products, such as sauerkraut,
           | yogurt, kefir, and tempeh. Homemade is where all the flavors
           | are preserved.
        
         | FpUser wrote:
         | I used to make "Kombucha" in the 80s when I still lived in
         | USSR. It tasted really good. The stuff they sell here in stores
         | tastes really bad, mostly like carbonated vinegar.
        
         | mypalmike wrote:
         | It's an acquired taste. Circuit boards, that is.
        
           | qup wrote:
           | You can season them up pretty well. I like the classic
           | seasoning combo of brow sweat, flux, and hardened cigarette
           | tar.
        
         | anonzzzies wrote:
         | Wrong Kombucha then. Source: Kombucha brewer.
        
       | PedroBatista wrote:
       | Great.. now "they" _really_ won 't shut up about Kombucha..
        
         | Lapsa wrote:
         | more of a carrot juice enjoyer but I think I will give it a try
        
         | fit2rule wrote:
         | [dead]
        
       | rotten wrote:
       | I look forward to the AI enhanced SCOBY life forms taking over
       | the world.
        
         | Oxidation wrote:
         | And I thought the Accelerando lobsters and Sheena 5 squid were
         | out there!
        
       | procparam wrote:
       | The mat at the top of the kombucha is not the SCOBY. It is a
       | waste product of the SCOBY - just a big slab of cellulose. This
       | is a misunderstanding that I've seen people on r/kombucha get
       | pretty upset about
       | 
       | The actual SCOBY is in the kombucha itself, not the cellulose.
       | It's pretty easy to prove; when I made kombucha I would throw out
       | the mat after every batch and save some of the liquid to use as
       | starter for the next.
        
         | richeyryan wrote:
         | You also don't need the mat, also known as the pellicle, to
         | start brewing kombucha. It is entirely redundant. Just get a
         | couple of bottles of unpasteurised, unflavoured kombucha and
         | use that as your starter, along with the fresh tea and sugar.
         | Those kombucha starter kits with a pellicle are just a big
         | scam.
        
           | rcpt wrote:
           | You can just use whatever store bought Kombucha to get going.
           | Of course if you find any scoby on Craigslist it's guaranteed
           | to be an interesting encounter
        
         | barbazoo wrote:
         | I didn't know that, thanks for mentioning it.
        
         | vbezhenar wrote:
         | Do you have any reference? I don't think that's strictly true.
         | I agree that this big slab is just some kind of protection, but
         | if you would look at the bottom part of this slab, you would
         | see threads, like small seaweed which "grow" from this slab. My
         | understanding is that kombucha is a symbiotic mix between those
         | threads (it's actually Yeast fungus) and bacteria in the
         | liquid. Liquid does contain some parts of fungus, of course, so
         | you can throw out the entire slab and new slab will grow
         | eventually, but you're throwing lots of yeast and its
         | protection. So your kombucha will take much more time to brew
         | and final result will not have the same proportions of
         | components as "properly" brewed kombucha.
        
           | ValentineC wrote:
           | > _My understanding is that kombucha is a symbiotic mix
           | between those threads (it 's actually Yeast fungus) and
           | bacteria in the liquid. Liquid does contain some parts of
           | fungus, of course, so you can throw out the entire slab and
           | new slab will grow eventually, but you're throwing lots of
           | yeast and its protection._
           | 
           | On the other extreme: if one has an old enough continuous
           | ferment, a lot of yeast will settle at the bottom,
           | potentially affecting the end result.
        
       | lancesells wrote:
       | https://archive.is/N98MG
       | 
       | Edit: Ignore. As commenter pointed out it's still paywalled.
        
         | comprev wrote:
         | This snapshot doesn't circumvent the paywall
        
       | avian wrote:
       | Can't read the article behind the pay wall, but possibly it's
       | based on this preprint:
       | 
       | https://arxiv.org/abs/2302.03984
        
         | infotropy wrote:
         | Oddly not paywalled for me but yes, the article is based on
         | that preprint.
        
       | durpleDrank wrote:
       | I had a HORRIBLE epic that spanned 2-3 years of unknown gastro
       | problems. I blame Kombucha 100% for rotting my insides. A cup
       | every now and then is ok but if you drink it daily (like I did)
       | in large doses (like I did) and make your own (which I tried to
       | save money) you'll soon realize it's essentially VINEGAR. I wont
       | get into the specifics but stay away from this stuff at all cost.
       | Try some cashew yogurt or other pro-biotic foods. Long term
       | Kombucha drinkers tread lightly.
        
         | Carrok wrote:
         | How much were you drinking? I have never heard anything like
         | this.
         | 
         | If you brewed it at home, then you should know that yes,
         | acetobacter the bacteria part of the SCOBY converts the alcohol
         | that the yeast creates from the sugar into acetic acid. Vinegar
         | is 5-8% acetic acid.
         | 
         | This isn't secret, sacred knowledge. Sounds like you over did
         | it, no need to spread your FUD around.
        
       | nyfern wrote:
       | Cheap, light, flexible, yet robust circuit boards are critical
       | for wearable electronics, among other applications. In the
       | future, those electronics might be printed on flexible circuits
       | made out of bacterial cultures used to make the popular fermented
       | black tea drink called kombucha, according to a recent paper
       | posted to the arXiv preprint server.
       | 
       | As we've reported previously, making kombucha merely requires
       | combining tea and sugar with a kombucha culture known as a SCOBY
       | (symbiotic culture of bacteria and yeast), aka the "mother"--also
       | known as a tea mushroom, tea fungus, or a Manchurian mushroom.
       | It's akin to a sourdough starter. A SCOBY is a firm, gel-like
       | collection of cellulose fiber (biofilm), courtesy of the active
       | bacteria in the culture creating the perfect breeding ground for
       | the yeast and bacteria to flourish. Dissolve the sugar in non-
       | chlorinated boiling water, then steep some tea leaves of your
       | choice in the hot sugar-water before discarding them.
       | 
       | Once the tea cools, add the SCOBY and pour the whole thing into a
       | sterilized beaker or jar. Then cover the beaker or jar with a
       | paper towel or cheesecloth to keep out insects, let it sit for
       | two to three weeks, and voila! You've got your own home-brewed
       | kombucha. A new "daughter" SCOBY will be floating right at the
       | top of the liquid (technically known in this form as a pellicle).
       | 
       | Beyond the popularity of the beverage, kombucha cultures hold
       | promise as a useful biomaterial. For instance, in 2016, an Iowa
       | State professor of apparel, merchandising, and design named
       | Young-A Lee gained attention for her proof-of-concept research in
       | using dried SCOBY as a sustainable leather substitute for
       | biodegradable SCOBY-based clothing, shoes, or handbags. In 2021,
       | scientists at Massachusetts Institute of Technology and Imperial
       | College London created new kinds of tough "living materials" that
       | could one day be used as biosensors, helping purify water or
       | detect damage to "smart" packing materials. Experiments last year
       | by researchers at Montana Technological University (MTU) and
       | Arizona State University (ASU) showed that membranes grown from
       | kombucha cultures were better at preventing the formation of
       | biofilms--a significant challenge in water filtration--than
       | current commercial membranes.
       | 
       | "Nowadays kombucha is emerging as a promising candidate to
       | produce sustainable textiles to be used as eco-friendly bio
       | wearables," co-author Andrew Adamatzky, of the University of the
       | West of England in Bristol, told New Scientist. "We will see that
       | dried--and hopefully living--kombucha mats will be incorporated
       | in smart wearables that extend the functionality of clothes and
       | gadgets. We propose to develop smart eco-wearables which are a
       | convergence of dead and alive biological matter."
       | 
       | Adamatzky previously co-authored a 2021 paper demonstrating that
       | living kombucha mats showed dynamic electrical activity and
       | stimulating responses, as well as a paper last year describing
       | the development of a bacterial reactive glove to serve as a
       | living electronic sensing device. Inspired by the potential of
       | kombucha mats for wearable electronics, he and his latest co-
       | authors have now demonstrated that it's possible to print
       | electronic circuits onto dried SCOBY mats.
       | 
       | The team used commercially sourced kombucha bacteria to grow
       | their mats, then air-dried the cultures on plastic or paper at
       | room temperature. The mats don't tear easily and are not easily
       | destroyed, even when immersed in water for several days. One of
       | the test mats even survived oven temperatures up to 200deg C
       | (392deg F), although the mats will burn when exposed to an open
       | flame. Adamatzky et al. were able to print conductive polymer
       | circuits onto the dried kombucha mats with an aerosol jet printer
       | and also successfully tested an alternative method of 3D printing
       | a circuit out of a conductive polyester/copper mix. They could
       | even attach small LEDs to the circuits with an epoxy adhesive
       | spiked with silver, which were still functioning after repeatedly
       | being bent and stretched.
       | 
       | According to Adamatzky et al., unlike the living kombucha mats he
       | worked with previously, the dried SCOBY mats are non-conductive,
       | confining the electrical current to the printed circuit. The mats
       | are also lighter, cheaper, and more flexible than the ceramic or
       | plastic alternatives. Potential applications include wearable
       | heart rate monitors, for instance, and other kombucha-based
       | devices. "Future research will be concerned with printing
       | advanced functional circuits, capable for detecting--and maybe
       | recognizing--mechanical, optical, and chemical stimuli," the
       | authors concluded.
        
       | LoganDark wrote:
       | Haven't seen the word "SCOBY" in years. I think the first and
       | only time I saw it was in an episode of JESSIE[0]...
       | 
       | [0]: https://jessie.fandom.com/wiki/Moby_%26_SCOBY
        
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