In the paper Instant Inkjet Circuits: Lab-Based Inkjet Printing To Support Rapid Prototyping Of Ubicomp Devices researchers Yoshihiro Kawahara of the University of Tokyo, Steve Hodges of Microsoft Research and Benjamin Cook, Cheng Zhang and Gregory Abowd of the Georgia Institute of Technology discuss this innovative and low-cost method of electrical prototyping.
Using silver nanoparticle inks this is an additive production technique that overcomes the problems of subtractive technologies such as PCB milling machines and commercial vinyl cutters. Recent advances in materials sciences have given us commercially available conductive inks that require little post processing.
Print on paper or plastic. Add protective coverings. Make flexible circuits with the bend radius of a ball point pen.
Printing digital is a powerful prototyping tool, but anyone who likes building digital artifacts — digital crafting — should look at it. For example, the team instrumented a plush toy with a printed capacitive sensor ribbon, enabling the toy to react differently depending on how it is touched.
The paper offers clear directions — part numbers, substrate types, practical advice — for DIY people. For example, they compare conductive double-sided adhesive tape to silver epoxy for attaching components to paper.
For their experiments they used an $80 Brother inkjet fitted with empty refillable cartridges and commercially available conductive ink. Using this low-cost kit they printed capacitive touch sensors, antennas and interaction sensors using time domain reflectometry.
The Storage Bits take
Re-purposing high-volume, low-cost consumer technologies - such as inkjet printers or SATA drives - for more specialized uses has a long and valuable history. As the paper points out, the researchers have just scratched the surface of what is possible with inkjet printing.
For example, how about multi-layer printed circuits? Using origami techniques it should be possible to build 3D structures with embedded circuits.
If inkjet printed circuitry generates even half the interest that 3D printing has, we'll see an explosion of uses for home and lab users. Anything that makes innovation easier and cheaper is good for technologists everywhere.
Comments welcome, of course. Where do you see this technique being applied? For more on UbiComp — ubiquitous computing — see this post.