Keywords: Silver nanoparticle, CNT, conductive ink, paper electronics, electrowetting, inkjet printing, ultrasonic-jet printing
Summary:Printing paper electronics has become more and more an attractive emerging topic currently, insomuch as certain printable conductive inks are highly demanded but development is not slow mainly due to the difficulty of solving oxidation problem for metal-based inks. Organic conductive polymer or carbon based inks, such as PEDOT:PSS and CNT inks, could be good candidates because of flexibility, which is well coupled with flexible paper, but their conductivity, when inkjet printing, is poor. Here we report the CNT ink composited with silver nanoparticles (AgNP/CNT ink), showing the high conductivity enough high to be used for the power lines for electrical circuit. Achieved sheet resistance was less than 0.2 /sq for printing repeated with four times by using a simple office inkjet printer. Most significant feature is the very high flexibility of this hybrid AgNP/CNT ink, keeping the conductivity over 180 degree bending curvature. With this hybridized carbon ink with metal particles, we successively demonstrated the various printed paper devices, such as paper RFID antenna, paper display, paper heater and paper temperature sensor.