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Saturday 19 May 2012

Conductive ink lets you freehand circuits on the cheap


silver-ink-on-glass
Jordan likes the flexibility that conductive inks offer when putting together electronic circuits, but says that they are often too expensive to purchase in decent quantities, and that they usually require substrate-damaging temperatures to cure. After reading a UIUC Materials Research Lab article about making conductive ink that anneals at relatively low temperatures, he decided to give it a shot.
Jordan started out by picking up various chemicals and lab supplies online, setting up shop at Pumping Station: One. The process is pretty straightforward, and seems like something just about anyone who took high school chemistry can manage. That said, he does note that some of the chemicals, such as Formic Acid, can be quite painful if mishandled.
After just a few minutes of work and about 12 hours waiting time, [Jordan] had himself a decently-sized vial of conductive ink. He tried it out on a few different substrates with varying results, and in the end found that etched glass made the best circuits. He says that there are plenty of experiments to try, so expect even more helpful info from him in the near future.

Conductive ink circuit experiments


This glowing LED is proof that the experiments Nvermeer is doing with conductive ink are working. We’re filing this one as a chemistry hack because  you need to hit the lab ahead of time in order to get the conductivity necessary for success. He reports that this technique uses a copper powder suspended in an epoxy intended for spray painting. Before mixing the two he etched the powder in ammonium persulfate, then washed it in deionized water which made it a much better conductor.
We gather that the ink was applied with the brush seen in the photo. But since this uses that spray paint friendly solution to host the copper powder we wonder about stenciling with something like masking tape in order to spray the circuit paths onto the substrate.



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