Make Conductive Silver Ink (complex ion based)

Make Conductive Silver Ink (complex ion based)


WARNING: Ammonia solutions have a strong smell, silver salts tend to stain and formic acid is corrosive. Gloves should be worn and this experiment should be performed outside or in a fume hood. Greetings fellow nerds. In this video we’re going to make conductive silver ink. But first I need to crush your expectations. This is not cheaper or better than commercially available conductive inks. Our objective here is to explore the science. First we take 1g of silver acetate and put in a magnetic stir bar. Then we add 2.5mL of concentrated ammonia solution. The solution is stirred for several minutes until all the silver acetate is completely dissolved. What’s happening here is the ammonia is reacting with the silver acetate to form diamminesilver acetate. When it’s clear we then slowly add 0.2mL of formic acid drop by drop. What’s happening is the formic acid is reacting with the excess ammonia to form ammonium formate. Later we will use it to reduce the silver into metal but a bit of it reacts prematurely to produce silver particles seen here. When all the formic acid is added and thoroughly stirred, the solution is capped and allowed to react overnight. Here we are the next day. There are some unwanted silver particles in the ink. I recommend removing the particles by filtering the solution through a syringe filter with 0.2 micrometer pores. This is very important for those of you who will be using this in an inkjet printer to print circuit boards since the particles might clog your inkjet printer head if not removed. And there we have it clear, particle free ink. Now to test it. Here we have a bare circuit board without any copper on it. Now we just simply apply some ink. I have crappy art ability which explains why I’m a chemist but you get the idea. I recommend using a modded inkjet printer or a 3D printer that’s been programmed to print a single layer. Anyway once you’ve drawn a pattern let it dry. What’s happening here is the ammonia is evaporating and the formic acid reacts with the silver ions to form elemental silver that precipitates out. When most of it has reacted the board is then heated to one hundred celsius and the particles of silver are sintered together to form a highly conductive bond. Some of you may be asking if this can be done on paper. Unfortunately this particular type of conductive ink does not work well with paper and just turns to silver black. I recommend using a particle based conductive ink rather than a complex ion based ink like this one. Anyway, let’s test its conductivity. Here I am with an ohmmeter and there it is. A relatively low resistance for a conductive ink. So there we have it, particle free conductive silver ink. Thanks for watching. The inspiration for this video came from this article. In this video we’ll be making silver mirrors In this video we’re going to make silver acetate.

95 Comments

  1. Brazil. You must have a license from the federal police to acquire it. I am not saying its impossible, but its very bureaucratic. Plus, we got a lot of ants. JK XD

  2. I noticed that the resistance (if that's what you're measuring) continues to go down as you're holding the probes to the ink. Is this a chemical process or just some quirk of the ohmeter?

  3. Hi NurdRage, is ut possible you could go into the chemistry of fire gel? You know, the stuff they use for burn scenes in movies? I feel like you could do a few great episodes of that! Anyways, I love you're videos. Thank you for informing and entertaining us all!

  4. Could you please upload something about white phosphorus, I've got some chunks about the size and shape of cigarettes imersed in water and I dont have the guts and knowlege yet to cut them…

  5. I find it so crazy that something that looks exactly like water (albeit a lot more viscous) can dry into something so metallic. It's a mind-blower.

  6. Printing a pcb instead of etching it.

    Now to find a printer that will print on plates with this ink, a 3D printer, and then I will TAKE OVER THE WORLD!

  7. NurdRage, I was wondering, what materials compose the stirring bar? Is it a material that is resistant to most chemicals, or do you just not use it for the experiments that would harm it?

  8. @ the end of the video you said that the ink just turns black on paper. Is it cuz the ink is reacting to the bleach or the titanium dioxcide the use to make paper white?

  9. nope, silver is the SECOND, after gold which is the most conductive. Copper is third, and finally do not compare the commercial inks, which may be compounds, to pure metals. compounds can take on completely different characteristics than their parent elements, and sometimes a compound may function better in an application than a pure element.

  10. this lasts much longer and won't produce the dangerously explosive nitrides like the silver nitrate based versions.

    So go for it 🙂

  11. Hi, very interesting the ink!! I read this paper a few months ago…
    I'll try to use in my inkjet to print complex circuits!
    I was thinking, if you use cupper acetate, will work too?

  12. wow, I just checked and you are right. I always heard it was gold, silver, copper. I guess they (whoever I heard it from) was wrong too.

  13. Actually, according to Wolfram silver IS the most conductive metal. the thing that makes gold better than silver in terms of conductivity is that gold does not tarnish or corrode.

  14. So Really a much simpler and faster method would be to put copper carbonate dust into a chamber, dump ammonia like you did, THEN acetic acid in, and cap it it really quickly, as the pressure will push CO2 into water creating carbonic acid, reacting with ammonia, and this will decompose just as quickly as ammonium formate, correct? So the carbonate route would be better, as youll make acetates, and the reaction will proceed faster.

  15. cool..but can you control its resistance.. i mean 4 ohms not alot but what if the next batch has 8 .in some circuits that might be a problem.. like amplifier circuits..anyway im stretching it i know… cool vid

  16. silver acetate, is that reated with vinegar? acetic acid? when i use citric acid to clean my silver post anneal, is that silver citrate? does it have any aplication? would copper knock it out of suspension? ag(citrate) + cu = cu(citrate) + ag???????? thanks for any help.

  17. can you use silver nitrate from nitric acid? i.e silver refining? you could draw on copper with this too? dont know about the fuse bit at the end working though.

  18. I don't think that oxalic acid is able to reduce aluminium ions to metallic aluminium. The first thing that comes to mind when thinking about copper ions are copper(II) ions, which are only soluble in an excess of concentrated ammonia, but I don't know how [Cu(NH3)4]^(2+) will react with oxalic acid, but it may be worth a try. Gold will form some miscellaneous Au2O3*x NH3 (x=2 or 3) precipitates with ammonia, but most definately will be reduced by oxalic acid,

  19. Very nice,, but really tough to get those chemicals.. This is another approach, poor comparing to the silver but still cheaper and can be truley done with things from home: Just search in youtube for dpSnjNkisOs

  20. Hello.Really awesome tutorial. Would it perhaps be possible to use heat transfer paper because that can handle the heat and also photo resistant paper or does it not work wit all types of paper

  21. hello again, sorry using this post, but would you have some video how to make KAu(CN)2 ? it is much used in electroless plating.

  22. NurdRage, in the supplementary information of that paper it says you can add 10% 2,3 butanediol (by volume) which serves as both a humectant and viscosifying aid. You should add it and try to apply the ink on paper again.

  23. Hi guys .. I have an lil question for you .. is there a way to skip formic acid or substitute it to reduce silver acetate into pure silver ? … Im not the chem dude im programmer and electrical eng .. so chemistry is liiitle big question to me … but I dont have acess to formic acid next 3 days and I pretty need to do this ….. thx

  24. Sir, Is it you can Possible make DIY Silicon ink and Paint Video ??
    How to make DIY silicon ink 2019.
    Please, Sir it will useful for our school science Project 😭😭😭😭😭Please Sir.

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