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Input Devices Technology Build

Silver Pen Allows For Hand-Written Circuits 161

Zothecula writes "People have been using pens to jot down their thoughts for thousands of years but now engineers at the University of Illinois have developed a silver-inked rollerball pen that allows users to jot down electrical circuits and interconnects on paper, wood and other surfaces. Looking just like a regular ballpoint pen, the pen's ink consists of a solution of real silver that dries to leave electrically conductive silver pathways. These pathways maintain their conductivity through multiple bends and folds of the paper, enabling users to personally fabricate low-cost, flexible and disposable electronic devices."
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Silver Pen Allows For Hand-Written Circuits

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  • Not slashdot too! (Score:5, Insightful)

    by Anonymous Coward on Wednesday June 29, 2011 @09:48AM (#36610974)

    These things have been around for decades, fuck knows why this is suddenly news.

    • by Anon-Admin ( 443764 ) on Wednesday June 29, 2011 @09:58AM (#36611112) Journal
      No kidding! Heck, 25 years ago My self and a friend used a felt tip one to draw a set of lines on a wooden fence. A set of nails and alligator clip wires and a little hacker engineering and we had the neighbors phone line on the window sill. Worked ok for about 2 weeks, provided it was not raining. Then it broke down enough that it did not work.
    • by dohzer ( 867770 )

      Isn't that what people used to unlock restricted multipliers on microprocessors? Or did those pens us a different conductive metal?

    • by AmiMoJo ( 196126 )

      Indeed, if you look at many old (1980) PCBs you can see how they were designed by hand. They would prototype with a pen and then use that as a template to make masks for etching. There is something quite beautiful about those hand drawn layouts, devoid of straight lines and equal spacing everywhere.

      • Prototyping wouldn't normally be done using using conductive pens. The hand drawn stuff was usually a resist pen on the actual copper-clad board, then etched.

        • by cvtan ( 752695 )
          You don't even need special resist pens. You can use ordinary indelible markers to draw on the copper and then use it as resist to etch the boards. Done it myself several times. OK if you only need one board for prototype. As far as the original article goes, silver loaded paint has been around for ages >40 years. It is called silver print. Not sure I would describe it as a way to make cheap circuits since I remember it being pretty expensive. See http://www.mouser.com/search/refine.aspx?N=42949533 [mouser.com]
        • I used to draw the layout by hand on a transparent sheet, then photo-transfer it to a circuit board with a light-sensitive coating on the copper. Develop the stuff, wash away the light-exposed parts and etch. No "prototyping" though - just a teenager building radios and amplifiers in his basement lair....
      • by Wansu ( 846 )

        We used black masking tape of various widths on a clear mylar sheet, typically at 2:1.

        The advantage of hand layout is you can create virtually any shape you need. This is important for power electronics where wide traces are needed to carry large currents or to conduct heat away from components.

        • Yep that's how I made my first circuit board too. You could also buy pre-printed stickers for DIPs and other common shapes like a pad with 3 holes spaced for transistors etc.
    • It's not news but, in slashdot, it's entertainment.

      Observe how this obvious old news generate a greater response than today's average.

    • I've been using them for almost my entire EE career. I have a small can of conductive paint as well. You can buy conductive fabric and thread too.

    • In defense, this might be the first time a ball point pen has been used with conductive ink. While I've used conductive ink on boards before, they have all been felt tip pens. What benefit does a ball point have over felt tip? I have no idea.
      • by vlm ( 69642 )

        What benefit does a ball point have over felt tip? I have no idea.

        Doesn't dry out as quick when the cap is off. You get to use it for more than 15 minutes.

        The more important reason is probably to avoid patents.

        • Yea, but do you know how well a ball point pen works on PCB? Pretty poorly, which is why we use felt.

          I'd bet a good chunk of money this isn't even the first 'ball point pen with conductive ink', its more likely that intelligent people realized a long time ago that ball point pens work really poorly on surfaces with no texture to cause them to roll ... like say a perfectly smooth fibreglass PCB backing that you'd want to draw conductive lines on.

    • I think the point is that these have a ball at the end, so you can make very fine circuit diagrams. Those other circuit diagram pens are more like a ink-style pen, where if you press too hard it all comes out. Plus it's hard to draw fine lines with current pens.

      It's similar to the difference between a old style ink pen and a ball-point pen -- they both serve the same purpose, but the ball-point pen is much easier to use with less mess.

    • It's not "suddenly news". It's a decades-old dupe that finally cleared queue.
    • I too would like to know what the major innovation is? Is it just a bunch of freshman who didn't know about this before and didn't bother doing a Google search?

    • Re:Not slashdot too! (Score:5, Informative)

      by Tx ( 96709 ) on Wednesday June 29, 2011 @10:22AM (#36611438) Journal

      The article fails to explain what's new here, a major failing since most every slashdotter will have heard of circuit repair pens. These guys apparently used silver nano-particles and hydroxyethyl cellulose [physorg.com] to create a flexible conductor, presumably much more so than the circuit repair pens that have been around forever. I must admit I've never tried using a repair pen on something flexible, but I'm guessing it dries pretty rigid.

      • Nope, as I pointed out on El Reg - pretty flexible:

        http://www.evilmadscientist.com/article.php/mobiuscircuit [evilmadscientist.com]

        From 2009

      • Re:Not slashdot too! (Score:4, Interesting)

        by xded ( 1046894 ) on Wednesday June 29, 2011 @01:03PM (#36613682)

        Original article here [wiley.com] (sorry, no free version available). I find ridiculous that they provide (mostly self) references to existing art, but they fail to mention commercial felt-tip silver pens.

        By a quick look at the paper, their ink has a resistivity of 2*10^(-4) Ohm*cm (25 C print temperature) which is not so lower than the 5*10^(-4) Ohm*cm commercially available ink [mgchemicals.com]. They do reach lower resistivity, but with high temperature annealing, so it cannot be compared directly (and they fail to).

        Maybe their ink is more flexible, but again they fail to provide comparison with existing ink.

        Their ink has probably lower viscosity due to the use of nanoparticles (they are working between 1 and 10 Pa*s) and this probably allows for the use of rollerball pens, but if felt-tip pens are working fine with a most likely cheaper ink, why should I care?

        However they do manage to master the acronyms creation art, providing the catchy PoP shorthening for their groundbreaking pen-on-paper circuit drawing approach...

    • Being able to make the leads with a pen is all very nice, but what about actual components? Call me when you can draw a functioning capacitor, transistor, etc. Until then, I don't really know what you'd do with this.
      • I suspect if you drew the symbol for a non-polar capacitor on regular paper, that you would actually make one. They might even be useful in high-frequency applications!

        Ditto for a resistor, although you might need a lot of squiggles for it to resist much.

    • These things have been around for decades, fuck knows why this is suddenly news.

      Probably because the original came out before many /.rs were born and somebody just re-discovered it. Next week, there will probably be a post about this crazy idea on how to etch our own circuit boards.

      • by treeves ( 963993 )

        Maybe they need to post stories like this just to give all us old /.ers a chance to come on and say that we've been using these things since before yer momma was born, and such.

        • ...the future crusty old bastards are already drinking the Kool-Aid.

          Of course the same youngins who think the silver pen is a new invention probably won't understand the Kool-Aid reference.

  • by chinton ( 151403 ) <.moc.liamg. .ta. .todhsals-100notnihc.> on Wednesday June 29, 2011 @09:48AM (#36610976) Journal
    It comes in handy when your man-animal may be spying to steal your teleportation secrets...
  • Not really new... (Score:1, Insightful)

    by drussell ( 132373 )

    This is not really new stuff... Silver pens for "circuit repair" have been available for ages... They made a ballpoint version.

    • by v1 ( 525388 )

      indeed. the previous versions have all been markers afaik. I wonder how well such a thin line from a ballpoint pen works? They probably had to up the conductivity a lot since when you're drawing a 1/8" line with a marker you don't need super high grade conductivity.

      But then again the ballpoint pen probably won't work on nearly as many surfaces as the old markers do.

      • I have one with a tip that's not much thicker than a standard ball point pen line. Thus far it's never given me a flaky connection but it's not like I'm running 50w through it or drawing traces longer than a few centimeters. I guess this is for people who like to free-hand multi-layered A4 sized PCBs...

    • This is not really new stuff... Silver pens for "circuit repair" have been available for ages... They made a ballpoint version.

      This is not really new stuff... Silver pens for "circuit repair" have been available for ages... They copied a ballpoint version.

      FTFY.

      -AI

  • Amazing!!!! (Score:5, Informative)

    by Lumpy ( 12016 ) on Wednesday June 29, 2011 @09:48AM (#36610998) Homepage

    They invented a product that has been available for over 20 years....

    http://www.mgchemicals.com/products/pens.html [mgchemicals.com]

    What's next from these ingenious companies?

    • by chinton ( 151403 ) <.moc.liamg. .ta. .todhsals-100notnihc.> on Wednesday June 29, 2011 @09:51AM (#36611024) Journal
      Next week, graphite in a wooden cylinder that can make marks on pressed and dried wood pulp.
      • by Anonymous Coward on Wednesday June 29, 2011 @09:58AM (#36611110)

        And it gets better - graphite is an electrical conductor! Now we've gone full circle.

      • by Tsingi ( 870990 )

        Next week, graphite in a wooden cylinder that can make marks on pressed and dried wood pulp.

        The Russians already invented those so that they could have a writing instrument that would work in weightless environments.

        • by tlhIngan ( 30335 )

          The Russians already invented those so that they could have a writing instrument that would work in weightless environments.

          Alas, too bad that story is false [snopes.com]. Both space agencies initially used pencils.

          Anyhow, one of the reasons for switching is the graphite dust that pencils emit - it could be troublesome since it hangs in the air - either fouling filters or could potentially short-circuit some of the electricals. And also the broken tips that happen annoyingly often - break the tip and it could send that

          • by mangu ( 126918 )

            It's not only in orbit that pencils cannot be used. Clean rooms do not allow pencils either. Graphite is dirty and messy.

      • Next week, graphite in a wooden cylinder that can make marks on pressed and dried wood pulp.

        Dear sir,

        Am intrigued by graphite in wooden cylinder. Please send more information and purchasing requirements.

        -AI

    • by h1q ( 2042122 ) <dragon@gmail.com> on Wednesday June 29, 2011 @09:58AM (#36611116) Journal

      What's next from these ingenious companies?

      A patent of course.

    • by Animats ( 122034 )

      Mod parent up.

      A conductive ink pen and a trace-cutter used to be standard equipment when debugging new PC boards. Today, you usually get it right the first time using CAD tools. Today's pin spacing is too close for hand drawing.

    • by vlm ( 69642 )

      They invented a product that has been available for over 20 years....

      http://www.mgchemicals.com/products/pens.html [mgchemicals.com]

      What's next from these ingenious companies?

      That product in general has been around something in excess of 40 years. Mostly used to repair scratched car rear-view mirrors.

    • by pruss ( 246395 )
      But the mgchemicals ones look felt tip, while these folks have a rollerball one. It looks like that may present particular difficulties. From the Advanced Materials article: "Central to the PoP approach is the design of a silver ink that readily flows through the rollerball pen tip during writing, does not leak from, dry out, or coagulate within the pen, and is conductive upon printing under ambient conditions. To create an ink with these attributes, we synthesized silver particles in an aqueous solution
  • Conductive ink pens have existed for years. I remember the time where overclocking certain AMD CPU's required one to bridge two points on the back of the chip.

  • Doesn't graphite do the same thing, more or less?

    • Pencil... Yes, that's how you scribble a resistor... Real lead pencils work even better.

    • Doesn't graphite do the same thing, more or less?

      For geeks with AMD CPUs and old ATI graphics cards, a sharp pencil was almost mandatory.

      Silver pens were permanent. If you fried your chip with the "pencil lead" mod, all you needed to do was grab your eraser and RMA!

    • With a tendency toward "less". Graphite is pretty conductive, fairly cheap, and has some useful mechanical properties(albeit often when mixed with other materials); but is a bit more resistive than most metals. Silver, by contrast, while more expensive, is among the most conductive materials commonly available(discounting oddities that are superconductive at atypical temperatures, or materials that have unusual properties in films a few atoms thick, and so on).

      If you don't need a particularly conductive
  • This seems neat for rapid prototyping and the hobbyist, but I wonder about 2 things. What is the cost since silver isn't exactly inexpensive? Also since I am not an electronics person how does one make connections to it since I would think that solder would burn paper?
  • Too bad the ol' Ag has gotten really expensive [yahoo.com] recently, "despite" the recession and all the all the stimulus.

    • They are expensive because of the recession. It is common for people to move their money into "safer" investments like silver and gold during a recession. That leads to a precious metals bubble making these investments highly dangerous, which of course, attracts even more money.

      • by vlm ( 69642 )

        Don't ignore the effect of printing staggering quantities of money... The "value" of an ounce of gold has always been about the cost of a man's suit or a really decent new handgun, and the "value" of an ounce of silver has always been about one unskilled laborers days pay or about a weeks groceries or about one box of ammo.

        Due to inflation, both long term and recently, both have skyrocketed numerically, but the value hasn't changed much.

        • Umm... wrong. There is no way your statements can be true both today and five years ago. Ag and Au prices have changed by a factor of five, whereas suits, handguns or 8 hours of minimum wage have changed by maybe 30% one way or the other. Currently, the price of gold is about six times of what I've paid for my bespoke suit; whereas the price of silver is still nowhere near a day's minimum wage -- and it especially wasn't five or ten years ago at a price of $7/tr oz...
        • The value of anything is purely subjective. Value is only defined in terms of social phenomena. There is no such thing as a 'bubble'. Bubbles are an attempt to rationalize events by fitting a narrative to them (see also all sports commentary [xkcd.com]).

          Value is random and turbulent, as are all markets. Markets are fundamentally unpredictable in the same sense that the weather is. There are no 'safe' investments, at any time. There are no oracles, there is no God, there is no solution to the halting problem. We are al

          • A bubble describes the social phenomena of the price of something rising because people believing it will continue to rise based on recent experience.

            "Markets are fundamentally unpredictable in the same sense that the weather is."

            Just like the weather you can predict where markets will probably be a few days from now, but there is no way to predict exactly where it will be five years from now.

            Just like the weather, general trends can be predicted far in advance, like winter will be cold and summer will be h

            • A bubble describes the social phenomena of the price of something rising because people believing it will continue to rise based on recent experience.

              A meaningless definition. Bubbles are defined in retrospect, i.e. the stock takes a nose dive, at which point you will construct a narrative that says it was supposed to happen.

              Just like the weather you can predict where markets will probably be a few days from now, but there is no way to predict exactly where it will be five years from now.

              I'm glad you understood the analogy. You don't seem to consider the conclusions though. Markets are less predictable than the weather; with weather systems all the inputs are known. Global Warming is an unpredictable emergent effect of random behavior. The analogous events in financial markets would be any market crash, and these uns

              • Many people recognized the US housing and .com bubbles before they burst. When the gold price crashes, you can dig up this comment and apologies.

                "Global Warming is an unpredictable emergent effect of random behavior."

                Scientists first predicted global warming many decades ago. If we had understood how the atmosphere work earlier we would have been predicted it even sooner.

                While I don't deny unpredictable things happen that can cause rapid rise in prices, a bubble is where there is a rise in price no reason r

                • Many people recognized the US housing and .com bubbles before they burst. When the gold price crashes, you can dig up this comment and apologies.

                  You're placing way too much faith in humanity's predictive power. We consistently overestimate it. Saying gold will crash is no more predictive, in fact, than saying it will snow in Phoenix. The when and the why are chaotic, and in the case of financial markets and other systems more complicated than snowflakes, fundamentally unknowable.

                  I have no idea other than naive delusion what would make you think that the actions of any individual human are predictable, let alone the collective actions of the species.

                  • If markets are truly they should be shut down because they are failing to serve their purpose in our economic system (not that they aren't doing a really crappy job anyway)

                    There is chaos and unpredictability in the markets, but they are still bound by the realities of supply and demand. Unexpected things can happen to supply and demand that can cause unexpected things to happen to the market, but if that isn't happening, then an unjustified price increase is probably a bubble.

      • They are expensive because of the recession. It is common for people to move their money into "safer" investments like silver and gold during a recession. That leads to a precious metals bubble making these investments highly dangerous, which of course, attracts even more money.

        True 'precious metals' or ones used by governments
        and countries as an exchange medium for debt and
        a hedge against inflation, cannot truly bubble. That
        is why we use them.


        An economic bubble (sometimes referred to as a speculative bubble, a market bubble, a price bubble, a financial bubble, a speculative mania or a balloon) is “trade in high volumes at prices that are considerably at variance with intrinsic values”.[1][2] It could also be described as a trade in products or assets with inflated val

  • I am surprised (Score:4, Insightful)

    by Osgeld ( 1900440 ) on Wednesday June 29, 2011 @09:59AM (#36611124)

    They didn't claim to invent the fucking paper too

    as others have pointed out this has been around for decades, and you can make your own ghetto version using copper radiator repair solution

  • So they spend time making something that already exists. Go to any art store and you'll be able to buy silver ink pens. And the roller variants don't work well on PCBs actually. So you're better of with other versions. I don't get how this sort of things even make it onto news sites. This has about the same quality level as the "force field" thing some computer science students came up with last month.
    • And the roller variants don't work well on PCBs actually.

      I think that's why everything in the article was pointing
      in every direction EXCEPT rigid PCBs., ie, paper.

      You are correct about everything else tho.

      -AI

  • It might also be useful for repairing electrical connections for circuit traces especially on boards that flex. I would love something like this since I could fix the window control on my car since the drivers door window controls no longer control the rear passenger side window and I don't want to spend the money for a new switch unit, if I can even find one.
  • http://www.radioshack.com/search/index.jsp?kwCatId=&kw=pen%20conductive%20ink&origkw=pen+conductive+ink&sr=1

  • I'd like to see how they gonna secure SMDs and BGAs to silver circuits scribbled on a bar napkin. Steve Wozniak no doubt would've loved if he coulda done that.

    • The EXACT same way you do it when your baking it onto the board? You glue it on. Of course on a normal PCB when its then baked to melt the solder, it gets a much stronger bond from the solder ... but glue is what holds the SMDs and such on until they get baked.

    • by pz ( 113803 )

      I'd like to see how they gonna secure SMDs and BGAs to silver circuits scribbled on a bar napkin. Steve Wozniak no doubt would've loved if he coulda done that.

      All you need to do is look at the linked article to see that they have done exactly this for paper circuits.

      Conductive ink / glue (silver dust in an adhesive vehicle) is pretty standard stuff. I use it all the time in my lab to make connections that are simultaneously mechanically secure and electrically conductive.

  • by jdastrup ( 1075795 ) on Wednesday June 29, 2011 @10:08AM (#36611248)
    That's what I would like to see, let's have someone put that metal jewelry and ink to use, attach a battery to your nose ring, embed an LED in your face, other cool stuff.
    • by vlm ( 69642 )

      That's what I would like to see, let's have someone put that metal jewelry and ink to use, attach a battery to your nose ring, embed an LED in your face, other cool stuff.

      Then there's the pr0n-industrial complex applications, that industry is always a leader in technology, at least behind the scenes. One person wears the battery, the other wears the cellphone motor, etc.

  • Maybe Zuckerberg can get a patent for "System and Method for Using a a Silver-inked Rollerball Pen in a Social Network".
  • The Gizmodo article linked in the summary is a blurb based on some research done at the University of Illinois, and, according to that blurb, published in the journal Advanced Materials ( http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1521-4095 [wiley.com] ). Looking at the current issue of Advanced Materials, the work doesn't show up, but there are a slew of other articles that the Slashdot crowd might find very interesting.

  • Okay, just joking. But IIRC the fellow who designed the 6502 that started the PERSONAL microcomputer revolution big-time, AKA Apple, Commodore, etc. drew the masks by hand and to most people's astonishment got it right on the first interconnect cut. Hand him the pen and let him loose!
  • This has been done for decades.

    Why don't you check some old 1960's Popular Mechanics on Google before embarrassing yourselves?

  • by Thuktun ( 221615 ) on Wednesday June 29, 2011 @12:03PM (#36612926) Journal

    Perhaps I've read too much Charlie Stross [wikipedia.org], but this story immediately think that users should be careful what they draw with this pen...

  • This pen is laying down particles of silver in a binder. Sadly, the article says nothing about resistance, but it's got to be much higher than what you'd get with a pure silver trace, no?

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