Fully printed organic thin film transistors (OTFTs) on a paper substrate. (a) Schematic of the device structure for a fully printed OTFT on paper. (b) Arrays of fully printed OTFTs fabricated on a paper substrate inkjet printed with the NIMS logo before adding the device. (c) An optical microscope image of fully-printed OTFT arrays. (d) A magnified optical microscope image of the individual device