Electrical Characterization of PEDOT:PSS Strips Deposited by Inkjet Printing on Plastic Foil for Sensor Manufacturing

Inkjet printing is a viable method for rapid and low-cost manufacturing of flexible sensors. In this paper, we study a technique for inkjet printing of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) strips. A low-cost inkjet desktop printer is used for the fabrication of PEDOT: PSS resistive strips on polyimide substrates. Accounting for several geometries of printed PEDOT: PSS strips, we assess the variability of the fabrication process. Owing to the printing process, we can easily choose the width, length, and thickness. We found that printed strips on polyimide foils show a conductivity equal to 115 S/cm, which linearly increases with the strip thickness. The maximum variability is lower than 13%. The frequency analysis shows a purely resistive impedance in the frequency range investigated (100 Hz-100 kHz). Moreover, the strips folded up to 1000 times shows a resistance variation lower than 6%. The study demonstrates that inkjet printing is a viable method for the simple, fast, reliable, and low-cost fabrication of PEDOT:PSS-based sensors on plastic substrates and circuit interconnections.