mohammad momeni-nasab

Ink-jet printing technology is one of the most promising printing techniques enabling fabrication of conductive patterns in a one-step and direct process. In this study, a microwave transmission line is fabricated on RO4003C substrate using water-based reactive inks and ink-jet printing technique. The fabricated transmission line structure includes an ink-jet printed silver line, a dielectric layer, and a continuous metallic ground plate. The conductivity of the printed line is measured using Four-point probe method. The electromagnetic wave absorption rate of the printed transmission line is simulated according to the measured conductivity, which proves a good agreement with the measured absorption rate at S band (2-4 GHz frequency range).

In recent years, much attention has been given to various printing techniques to produce low-cost electronic ingredients and equipment. Inkjet printing is one of the most promising methods for printing circuit ingredients in one step almost on any substrates. In this study, the inkjet printing technique was employed for chemical deposition of silver nanoparticles by ejecting aqueous solutions of silver nitrate as metal salt and ascorbic acid as reducing agent on flexible substrates such as paper and fabric. Inkjet-deposited silver patterns were used as capacitors in electrical circuits and their performance was tested. Different values of capacitance were gained by a simple change in the size and shape of the printed capacitor. The highest capacitance values gained on an inkjet-deposited capacitor (a parallel plate capacitor with 1 cm2 overlapped area) on paper and fabric were 85.1 and 1370 pF, respectively. Inkjet-printed capacitors (interdigital capacitors with six fingers) could display a capacitance around 20 and 6 pF on paper and fabric, respectively. Levels of capacitance achieved by the new inkjet deposition technique can successfully match and exceed the capacitance levels of conventional capacitors produced using current multi-step fabricating methods.