H. Chae, M. Jung, V. Soum, J. Lee, H. Kim, H. Cheong, T. Kim, S. Jeon, O-S Kwon, K. Shin
Keywords: thermoelectric, temperature sensor, inkjet printing, conductive ink, printed electrodes, paper electronics
Summary:Recently, printing temperature sensors have been significantly demanded in the paper electronics, such as electronic skin for robots, polymer chain reaction for DNA amplification. Here we present printing thermoelectric temperature sensors by using a simple home/office inkjet printer with a three different conductive inks based on carbon nanotubes (CNTs), silver nanoparticles (AgNPs) and PEDOT:PSS. Due to novel combination of electrical, mechanical and chemical properties of three distinct materials of carbon, metal and polymer: e.g., especially high flexible, good conductivity, non-reduction and non-high temperature curing, they showed superior materials for printable conductive ink especially for paper substrate. Most critical factors on fabricating of the CNT, AgNP, PEDOT:PSS inks were to provide the stable dispersive, to establish the proper viscosity and surface tension to eject well from an inkjet nozzle and to minimize the particle size for non-clog the nozzle. Three thermocouples of PEDOT:PSS/CNT, PEDOT:PSS/AgNP, and CNT/AgNP have printed on paper successively and investigated for Seebeck effects (Fig. 1). Additionally, these conductive inks can be applied for various good paper electric devices. For example, the electrochemical sensor for a glucose-sensor can be realized by functionalizing the electrodes via printing two different electrodes.