4 ms·

Conductive pens are already available and used for circuit board repair (I think resistance is too high for long traces), e.g.: http://www.circuitspecialists

Conductive pens are already available and used for circuit board repair (I think resistance is too high for long traces), e.g.: http://www.circuitspecialists.com/8420-p.html If you check the PCB forums, people are always toying with the idea of hooking these up to a plotter for DIY circuit boards without needing etching chemicals. Presumably these researchers have come up with a better one (probably more consistent flow).

delinka 15y ago
Seems many people are jumping on the "been doing it for years" bandwagon. Since I've never touched this stuff, I have questions: do the existing conductive pens work on paper? Can you take notebook or drafting paper, apply the existing conductive pen "ink" and get a functional circuit of reasonable size (up to the size of the paper) without burning up the paper? You mention that perhaps the resistance is currently too high and that these guys may have come up with something that has "more consistent flow." The news here is ink-on-paper makes circuits, not conductive pens have been invented for the first time.
- AretNCarlsen 15y ago
  The existing pens are intended only for minor PCB repairs. They are terribly expensive, as in $100/oz, have high resistance, and cannot be drawn with smoothly (like a pen). They are also not intended for the kind of flexing that you see on a piece of paper. Example (0.3oz for $30): http://www.amazon.com/gp/aw/d/B000B5YDT8 http://www.amazon.com/gp/aw/d/B000B5YDT8 Historically, you've been better off using conductive silver thread for flexible and on-the-fly circuits. Still expensive and resistive, but tolerably so. Example (82 ohms/ft, $5/yd): http://www.sparkfun.com/products/8544 http://www.sparkfun.com/products/8544
  - sorbus 15y ago
    They can be found for around $30/oz; the first google shopping result for "conductive pen" is 9 grams (0.317 oz) for ~$10. It seems to be the same one you linked to on amazon (is that the mobile version, by the way? Because there's practically no information on that page and it looks horrible).
    - AretNCarlsen 15y ago
      The cheaper $/oz is for nickel-based pens. I haven't ever encountered a nickel pen in person. Do they work as well as the silver-based?
ajdecon 15y ago
A big part of this is the more consistent flow, yes. Two of the major factors in the ink design were balancing the viscous properties of the ink (mildly shear-thinning, iirc) with the need to keep the silver nanoparticle concentration as high as possible. (Disclaimer: I am a former member of the Lewis group, but didn't work on this project myself.)
- NonEUCitizen 15y ago
  Do you know if they are also much more cost effective than existing pens ?
  - ajdecon 15y ago
    No idea, as no commercial-scale production has been attempted. This is all still lab-scale.

delinka 15y ago

Seems many people are jumping on the "been doing it for years" bandwagon. Since I've never touched this stuff, I have questions: do the existing conductive pens work on paper? Can you take notebook or drafting paper, apply the existing conductive pen "ink" and get a functional circuit of reasonable size (up to the size of the paper) without burning up the paper? You mention that perhaps the resistance is currently too high and that these guys may have come up with something that has "more consistent flow." The news here is ink-on-paper makes circuits, not conductive pens have been invented for the first time.

AretNCarlsen 15y ago
The existing pens are intended only for minor PCB repairs. They are terribly expensive, as in $100/oz, have high resistance, and cannot be drawn with smoothly (like a pen). They are also not intended for the kind of flexing that you see on a piece of paper. Example (0.3oz for $30): http://www.amazon.com/gp/aw/d/B000B5YDT8 http://www.amazon.com/gp/aw/d/B000B5YDT8 Historically, you've been better off using conductive silver thread for flexible and on-the-fly circuits. Still expensive and resistive, but tolerably so. Example (82 ohms/ft, $5/yd): http://www.sparkfun.com/products/8544 http://www.sparkfun.com/products/8544
- sorbus 15y ago
  They can be found for around $30/oz; the first google shopping result for "conductive pen" is 9 grams (0.317 oz) for ~$10. It seems to be the same one you linked to on amazon (is that the mobile version, by the way? Because there's practically no information on that page and it looks horrible).
  - AretNCarlsen 15y ago
    The cheaper $/oz is for nickel-based pens. I haven't ever encountered a nickel pen in person. Do they work as well as the silver-based?

ajdecon 15y ago

A big part of this is the more consistent flow, yes. Two of the major factors in the ink design were balancing the viscous properties of the ink (mildly shear-thinning, iirc) with the need to keep the silver nanoparticle concentration as high as possible. (Disclaimer: I am a former member of the Lewis group, but didn't work on this project myself.)

NonEUCitizen 15y ago
Do you know if they are also much more cost effective than existing pens ?
- ajdecon 15y ago
  No idea, as no commercial-scale production has been attempted. This is all still lab-scale.