New Conductive Ink Allows Circuit Prototyping With A Pen And Paper


Why spend time etching circuit boards and applying solder masks when all you really need is a rollerball pen and some paper? That’s what University of Illinois professors [Jennifer Lewis and Jennifer Bernhard] were asking when they set off to research the possibility of putting conductive ink into a standard rollerball pen.

The product of their research is a silver nanoparticle-based ink that remains liquid while inside a pen, but dries on contact once it is applied to a porous surface such as paper. Once dry, the ink can be used to conduct electricity just like a copper trace on a circuit board, making on the fly circuit building a breeze.

Previous ink-based circuit construction was typically done using inkjet printers or airbrushing, so removing the extra hardware from the process is a huge step forward. The team even has some news for those people that think the writable ink won’t hold up in the long run. The ink is surprisingly quite resilient to physical manipulation, and they found that it took folding the paper substrate several thousand times before their ink pathways started to fail.

While we know this is no substitute for a nicely etched board, it would be pretty cool to prototype a simple circuit just by drawing out the connections on a piece of paper – we can’t wait to see this come to market.

42 thoughts on “New Conductive Ink Allows Circuit Prototyping With A Pen And Paper

  1. The last paragraph in the journal article says that they designed it for low-cost. Hopefully that means a fairly low consumer cost, because making ink from pure silver is going to be $$$ as is.

    I’d say they won’t be available commercially for at least a year still, BUT they’re fairly easy to make yourself if you have a centrifuge and some chemicals laying around (PPA, Silver, diethanolamine, water, and hydroxyethyl cellulose).

  2. @Pilotgeek,
    While still cool, that only writes on hard surfaces, which makes me think it’s not a roller ball pen, but a felt-tip or paint pen. This loses the novelty of ink that won’t dry in a pen, but will dry on paper (that pen is presumably sealed more than a roller ball) and it’s not flexible (due to acrylic binder)

    @Alex and Boudico
    Why not regular glue of any kind, then just a blob of this touching the side?

  3. This technology has been around for years… A graphite pencil! (not really :p)
    I can’t wait to see this on shelves, although it will probably cost an arm and a leg (and your firstborn son)

  4. Haven’t you been able to buy conductive ink markers for about a decade at least? I seem to remember having seen these out there forever. Is it just a different type of conductive ink?

  5. I agree with Marco, inkjet traces would be more useful. Something conspicuously missing from this article is how the components are mounted to the paper and what makes them maintain solid electrical contact with the traces… Sure the traces are reliable but what keeps your SMD LEDs from popping off and getting lost in the carpet?

  6. Few things make me giggle like a school girl. I’m happy to say that news of a cheap conductive-ink ballpoint pen is one of them.

    It’d be great if they added a (light) adhesive to this stuff, so the SMD parts don’t go flying away when I sneeze. :) Make it tacky until it’s dry, with alcohol(s) as a carrier/solvent. Giggity.

    There’s the solution, GuiltyPixel. And if they DON’T include it, I’m sure a dab of cyanoacrylate (superglue) would help keep them in place.

    Wonder what would happen if you draw with this pen, right on your skin. Could I then stick LEDs and a uC onto myself, and would they then work as programmed? LOL Oh the potential for hilarity and Halloween costumes!

    Still reading through the details, so please don’t flog me too hard if my questions are answered therein.

  7. oh man, something to replace copper tape for repairing delaminated traces? Awesome. I didn’t realize that similar stuff currently exists, until earlier posters brought it to my attention. I know what my office is going to be ordering a case of. :)

  8. this is a very poor summary. conductive ink pens have been around for a very long time (i’ve heard folks say around 20 years, as this article has been making the rounds). there is one beside me.

    circuit prototyping has NOT traditionally been done with inkjet printers, and *that* is a new process only recently developed, and for which relatively few conductive inks exist. there has been a lot of research into using silver nanoparticles because of their relatively low resistance, and for their ease of jetting if you pair them with an appropriate carrier. there are a bunch of companies that currently do this, but their conductive ink is very expensive.

    using a large-tipped pen with conductive ink is /not/ meant as a replacement for rapidly prototyping or printing circuits with an inkjet process. inkjet allows extremely fine traces to be constructed — or even entire multilayer boards — and is in no way going to be replaced by the use of a giant pen and someones hand.

  9. haha can’t believe people are comparing this so the shitty conductive pens you can buy at radioshack. if you had ANY idea what you were talking about, you’d know that pen is a worthless sack a shit, so quit whining about this “being done already”, it hasn’t been done correctly at all.

  10. I’m confused. Can anybody tell me how this stuff is better (if at all) than the existing commercially available conductive inks?? Sorry for the scepticism, but I suspect that its another case of a research paper getting accepted because it has the word ‘nano’ in the title.

  11. @twopartepoxy & others – This is about being able to use conductive ink with a ball-point pen. Yes, conductive ink has been done for years, but this stands out because it is the right consistency to be used in a ball-point pen without clogging it or drying out.

  12. Glad they invented something I have been using for 40 years…

    Wow they are getting dumb researchers nowdays…

    And OOOH boy, ballpoint, yeah that has advantages over other methods… NOT. Ballpoints fail more times than marker types on different surfaces. Maybe I want to draw my duino circuit on a glossy magazine page!

  13. @Roman; we used to overclock our AMD XP-1800/2000 CPUs with pencils!
    @Pilotgeek beat me to it lol.

    @Jack, hmm, I have one right here. I can meg it to 1000v and it writes on anything. As thin as I can draw it, a 12″ line on 20-weight copier paper is still 0.19 ohms.

    Not bad for my $13 at Radio Shack. I bet this rollerball pen is $50+ if it ever makes it to market.

  14. I saw a similar product on the shelf at the local Radio Shack. it was not a roller ball, rather one of those felt tipped ‘paint’ pens. It worked pretty well on a frisbee I was adding some LED to. On paper it sucked up a lot of the ink. Would recommend a gloss or matte finish of some kind so its not so porous. I think the roller ball will give better precision and use less ink. already I’m thinking to create an adapter to drop it in to a plotter and print some paper circuits.

  15. Hell, I’m gonna start using iron for hooking up all my circuits from now on. It’s a lot cheaper than copper. I’ll just increase the amperage and voltage to overcome the increase resistance. Hey Roman, got any good sources for discreet components that work at 50+VDC?

  16. Nice, again the expense is likely to be high much like Wire Glue.

    Its essentially the same as the silver in those car demister repair kits, at least as far as it behaves.
    I have had some success making my own using an ultrasonic cleaner and silver gilding foil.

    It seems that according to the nice folks on 4HV you can improve on my discovery by using an ultrasonic fog generator (£12 from maplins) or just the element with a suitable driver- the higher frequency “chops up” the silver into smaller fragments.
    Not tried yet but should work…

    If anyone gets this to work please donate to keep us running, thanks so much.

  17. Hi
    I did try to make this ink as they shown in video. I spent $8000 to brig all these chemicals and equipments, After 3 experiments i get only 5ml ink. But that ink never goes from pen. Than i inkjet it on paper with big needle siring. So I saw up liar is non conductive when i scratch it than i found very pure silver liar on paper that was conductive, So I am telling you they are hiding things (some other chemicals) or some method so no body can get accurate result and also its really very expenses experiment.

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