First mightier than the sword, now mightier than the laser

Nano Drawing A flexible array of LEDs mounted on paper. Hand-drawn silver ink lines form the interconnects between the LEDs. Bok Yeop Ahn

We’ve long marveled at the wondrous creations enabled by 3-D printing. Well, now comes 3-D handwriting.

A plain rollerball pen filled with a conductive ink can draw circuits on a sheet of paper, where they can provide power to an LED display and an antenna, among other potential uses.

Researchers at the University of Illinois at Urbana-Champaign made a new type of liquid metal ink that stays liquid in a pen, but dries after being applied to paper, wood or another surface. The liquid consists of silver nanoparticles that were reduced in size using acid, and then modified with cellulose so the fluid has a more inky viscosity.

Draw a line, and when it dries, the result is a silver wire that can conduct electricity. Researchers built an LED display with their school’s initials, UIUC, and the lovely sketch below depicting a house and trees. The ink serves as wiring for the LED mounted on the roof of the house, and it’s powered by a five-volt battery connected to the edge of the painting, according to a UI press release.

While 3-D printers can also create customized circuitry, a handheld pen is a cheaper, more portable method, materials scientist Jennifer Lewis said. There’s no software required — just a steady hand. The pen would enable circuits to be drawn on small, oddly shaped surfaces, and it can work as fast as someone can move his or her hand.

"Sae-Han-Do" Sketch:  Jung Hee Kim

The team folded the paper to see how the circuits would up and found they needed to be folded several thousand times before the lines were broken, according to via PhysOrg.

The circuit pen could enable new disposable, bendable electronics and folded 3-D objects, the researchers said. They want to expand their palette to other types of conductive materials, according to UIUC.

The ink research, which was funded by the U.S. Department of Energy, was described in an early online version of the journal Advanced Materials.

[via PhysOrg]

16 Comments

Okay, the "Cool Factor" here is quite high... though I wonder what true economic value this has going forward, and whether our tax payers will see any return on their tax dollar investment (made by way of the DOE). People wonder where their tax dollars go, and here we certainly have one of those buckets...perhaps we can paint the cost on a piece of paper and see if it lights up? Just kidding...well, almost.

@JayArr
Main advance is the ink. Shot in the dark here: this ink could be used on an industrial scale to cheaply print circuit boards without all the usual vats full of chemicals. It also seems like this ink might be able to streamline the production of simple rigid-flex circuits. By Googling a bit, it seems that the military is interested in this stuff to be able to print out solar panels on thin, flexible materials (tents, uniforms). So yes, it looks like the taxpayers will get their money's worth.

Secondly: you're using THIS article to rant about wasted taxpayer money? This research is from U of Illinois... DoE probably funded this project to the tune of what? 100k$? 500k$? Drop in the bucket. The distribution of public funds is all about choices, and I'd personally give extra cash to dozens (if not hundreds) of university research labs and just build one less ship for the Navy.

I want one, this would be fantastic for prototyping.

They have had products like this out for decades. This may be a new working of the materials, but it is by no means as astonishing as the article makes it sound. We used them for drawing circuits on paper in general physics class.

the wowest, how much current do you think this can hold, anyways, i like to grab one of those!

What are the tattooing possibilities? I'll volunteer to have some Christmas lights attached to my arm...

First transistors built using paper as a structural and electrical component, September 2008

www.spectrum.ieee.org/computing/hardware/paper-transistor

"What are the tattooing possibilities? I'll volunteer to have some Christmas lights attached to my arm..."

hehe.. awesome idea!

"The team folded the paper to see how the circuits would up and found they needed to be folded [...]"

Perhaps you meant to write, "would [hold] up" instead? Confused me for only a moment, but missing words are far more annoying than misspelled words.

That said, this is REALLY awesome. Now, there's a simple product that will allow electrical engineers to prototype and play around with circuits without needing to bother with a board and all that wire-snipping. If only I'd had one of these pens in my high school engineering class!

"The team folded the paper to see how the circuits would up and found they needed to be folded several thousand times before the lines were broken"

How was folding the paper several thousand times possible??

Another pen with liquid LED ink and this pen to wire it up and you could have really cool tatoos.

@suggestivesimon, while FAR from being any sort of "rant," my comment was intended to elicit conversation and discussion, as well as being a general observation and query of minimally humoristic intent; though that aspect was apparently lost in 'translation' somewhere along the way. I favor investment in our universities and other land-grant institutions, and am certainly an advocate of research and technological advancement. Perhaps it would have been a good idea for the writer of this article to add more meat to her article, to provide a little more in-line context and depth to what she presented. And, yes, I do see embedded links to other articles/content...but who clicks on those?? ;-)

And how about solderability?? Or the components must be bound using conductive adhesive??

@JayArr...it is a brief article on a website meant to be such, get a subscription or click on a link provided, lazy as#, you are not that funny, to all who complain about these articles, fuc# off

@bioboy,

exactly... they have sold silver-ink pens at radioshack for probably a decade now

Wow, drchuck1, such a potty mouth!! If you were my son you'd be getting your mouth washed out with soap right now. Grow up just a tiny bit and maybe you will be allowed to sit at the grown-up table someday.

If you have nothing constructive or intriguing to say, please refrain from commenting at all.



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