I wonder how practical it would be for real life application since it looks fragile, it is currently deployed and tested. Even if not practical, concept is excellent technology demonstrator: downloadable printable sensors powered with surround electromagnetic radiation. Cool!
They use commercially available inkjet printers and commercially available conductive ink from Mitsubishi.
Project by: Yoshihiro Kawahara
|SenSprout printed moisture sensor deployed (source:Wired)|
I think this is Mitsubishi silver nanoparticle ink they mentioned: http://www.mitsubishiimaging.com/digital-imaging-diamond-jet-NANOINK.html
Applications of 2d printed electronic circuits are infinite, similar to 3d printing. Hopefully this technology will soon expand into DIY space. There are many corporate and academic developments in conductive inks, but conductive ink can be also produced in DIY / home lab setting (this one doesn't work on paper):
Ink video by NurdRage