Researchers craft a fully edible battery | Hacker News Reader

Researchers craft a fully edible battery

arstechnica.com

My first question was "but why?" and apparently it has more applications than one would think at first, as it says in the article: edible batteries in toys for kids would eliminate toxicity risk and supporting electronics that go inside our body (they are working in edible transistors).

I also wanted to highlight this hilarious phrase in the article:

> While all of these components are nontoxic and edible, the researchers clarify that a user is not supposed to eat the battery on purpose, which would obviate the whole point of making it rechargeable.

"Please don't buy our batteries for eating, eat a banana or something"

Now we need edible electronics and webcams, so you can eat a webcam - make photos inside, send them out of body - and... digest it...

We have edible, but not digestible wireless cameras already. Prepare for a slightly different noise when using the bathroom in the next few days/hours though.

https://www.mayoclinic.org/tests-procedures/capsule-endoscop...

That’s genius. Now I want to get one just out of curiosity. Looking at the cost though, I think I’m going to have to pass this one

... just to clarify, when you say pass ...

I chose my words carefully ;-)

Kind of already a thing although you have to pass this:

https://www.cancerresearchuk.org/about-cancer/tests-and-scan...

Another high value use might be long term surgical instruments that are meant to be left in the body for several weeks before degrading harmlessly. Imagine something like dissolving stitches.

Don't dissolving stitches already exist[0]?

> Absorbable sutures, also known as dissolvable stitches, are sutures that can naturally dissolve and be absorbed by the body as a wound heals.

[0]: https://www.webmd.com/a-to-z-guides/what-to-know-absorbable-...

Yes. Now imagine e.g. dissolving pace makers or whatnot.

I wonder what use that would have—maybe healing after heart surgery? Using a pacemaker as a crutch until your heart can beat on its own again?

a pacemaker is admittedly a poor example, but it's also just that: an example. I'm sure there's hosts of medical devices that would benefit from dissolving. Perhaps even devices that are infeasible currently because they don't dissolve.

Here and I was going to suggest they add a graham cracker crust.

> "Please don't buy our batteries for eating, eat a banana or something"

So much potential, which will be left unused...

"We don't recommend that you buy our batteries solemnly for the purpose of eating, but we won't judge you either."

"We don't recommend that you buy our batteries solemnly for the purpose of eating, but if you want to take a bite, the D-Cells are chocolate flavored."

I associate this style with soulless marketing campaigns. Thanks, marketing, for destroying language for me.

That was my intention - glad it worked!

> So much potential, which will be left unused...

Potential as in electric potential? :)

Oh hell... I cannot believe I missed that pun... :D

Or just coat the batteries in disgusting taste so kids don't put them in their mouth repeatedly.

This is a good idea, much like the usage of Bitrex in certain household items, mainly cleaning solutions.

https://news.ycombinator.com/item?id=34592137

Very quick math says this is much weaker than a potato battery, which is a fun comparison. [1] puts the capacity of a potato around 0.1 Wh, quite impressive. Using the numbers from TFA I get a capacity of 5.2 µWh [2]. For reference an AA battery is 4.275 Wh.

A spent potato battery is apparently not edible, but 5.2 µWh does not provide much power. Also a potato battery is not rechargeable, while this one is, if you do not eat it of course.

[1] https://sciencing.com/make-potato-battery-6537882.html - 0.5V * 10mA * 20 h

[2] 0.65V * 48 µA * 1/6 h (you get a 10 min runtime at the wattage)

P.S. I know this should be calculated in joules, but battery capacity is always listed in (k)Wh or mAh, so I kept to these units

edit: correct potato capacity calculation, was off by a factor of 10

> A spent potato battery is apparently not edible

Wait, really? What happens if you eat a used potato battery?

My guess is that it's full of a bunch of copper ions that are toxic

I went down the rabbit hole on this one and found this discussion from thenakedscientists.com:

https://www.thenakedscientists.com/forum/index.php?topic=474...

---

Is a potato used as a battery still edible?

This thread seems to be essentially all wrong. "What does this do to its edibility once the energy has been all used up? " The energy used to run the clock doesn't came from the potato. It comes from the coal used to smelt the zinc from its ore. "Not sure how it will taste, but it will reduce the ascorbic acid content." Probably true, but not a big deal "Potatoes have a higher content of vitamin C than even oranges do." Not true http://en.wikipedia.org/wiki/Vitamin_C#Plant_sources

"You will also get some metal ions in your potato. Copper ions, zinc ions, etc, depending on what your electrodes are." Not quite true, there's no "probably" about it. The energy is released by the conversion of metallic zinc to zinc ions.

"Perhaps some organometallic compounds." I doubt it; most organozinc compounds are not stable in the presence of air or water.

"Some of the metal ions may in fact be vitamins" No, they may be minerals which the body uses, but they can't be vitamins since ther are not organic compounds.

Nobody has mentioned the fact that spuds exposed to light generate toxic chemicals http://en.wikipedia.org/wiki/Solanine#Solanine_in_potatoes

The simple answer is no. Throw the used potato away.

----

Apparently potatoes are not natural batteries, the conversion of zinc to zinc oxide produces energy.

----

They dig zinc oxide out of the ground The add coal and heat it to get zinc 2 ZnO + C --> 2 Zn + CO2

If they just burned that coal they would get energy. This way some of that energy is "stored" by making metallic zinc.

When the zinc is oxidised that energy is released.

It's also plainly true that any battery with too much power, when bitten and chewed, would form lots of electrical shorts in your mouth and burn the hell out of your insides.

It's not obvious to me. Aren't there things like air-aluminum batteries, not that you'd eat them, but that would be inert if you did?

I constantly remind myself to stop using absolutes on the internet, yet I still do it.

Siths will be Siths

Potato batteries are back? Quercetin would be onion/apple flavor, riboflavin will be liver/egg flavor. Activated charcoal will prevent anything from being absorbed in the gut.

"Researchers find major storage capacity in metal-free aqueous batteries" https://www.inceptivemind.com/researchers-finds-major-storag... :

"The role of the electrolyte in non-conjugated radical polymers for metal-free aqueous energy storage electrodes." (2023) DOI: 10.1038/s41563-023-01518-z

"A sustainable battery with a biodegradable electrolyte made from crab shells" (2022) https://www.sciencedaily.com/releases/2022/09/220901135827.h... :

"A sustainable chitosan-zinc electrolyte for high-rate zinc-metal batteries" (2022) http://dx.doi.org/10.1016/j.matt.2022.07.015

Chitosan https://en.wikipedia.org/wiki/Chitosan :

> Chitosan /ˈkaɪtəsæn/ is a linear polysaccharide composed of randomly distributed β-(1→4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). It is made by treating the chitin shells of shrimp and other crustaceans with an alkaline substance, such as sodium hydroxide.

Is there a sustainable way to produce Chitosan, which is an electrolyte?

https://westurner.github.io/hnlog/ Ctrl-F "anode" :

> Here's a discussion about the lower costs of hemp supercapacitors as compared with graphene super capacitors: https://news.ycombinator.com/item?id=16814022

"Why Salt Water may be the Future of Batteries" https://youtu.be/vm2hNNA4lvM ($5/kwh, energy density, desalinization too, graphene production too)

Flow battery > Other types > Membraneless https://en.wikipedia.org/wiki/Flow_battery#Other_types

Now make edible LED's and other components and we can have some pretty fancy blinking light food!

Link to PDF of the paper:

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adma.2...

Page 7 has a photo of the battery, powering an LED.

Now we need to make marshmallow vehicles, breathable water pool, warm fire that won't burn, antigravity flooring in case children might fall down.

Child mortality has fallen almost every year since the 1800s. That doesn’t happen without advancements like this. Are you really advocating for higher child mortality?

Great. Now if I don't support these, I'm advocating for child suffering. Flawless logic there.

I mean yes? They made safe batteries for children toys. It’s an objectively good thing, stop being so miserable.

Not if they are terrible batteries in term of energy storage and cost. It's not objectively a good thing and I don't have to agree with you or this product to be not miserable.

Joking aside, a warm fire that won't burn and a breathable water pool would be endlessly entertaining.

It would probably be a billion times less powerful than a silicon chip (and only last a few days), but I wonder if one could make a potato into a cpu.

Maybe useful for mouth gadgets like this thing

https://www.augmental.tech/

Its called a fruit?

You can use a potato or an orange as a battery (just stick some wires in). It's not rechargable though.

This is a common misconception, the battery is NOT the fruit, it's the wires you stick into it.

Banana nuclear reactor?

https://jabde.com/2022/11/06/banana-fission-reactor/

> It's not rechargable though.

Renewable though.

It is not. The organic material isn't the part that gets used up, but rather the electrodes. The energy does not really come from the potato, just the chemistry environment. If you take the electrodes out and put them in a new potato, I don't think that will get you a fresh battery.

Oh, so the fruit is just being used as an electrolyte, not as actual energy storage?

Now I can finally have a battery-powered horse cart

But is it delicious? Until we get dessert batteries, meh.

I’ll let y’all try it and let me know how it is!

wasn't there a drinkable (alcohol~) battery some time ago?

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