Ulrike Herzau-Gerhardt, Frank Hilscher, Henning Nagel

Abstract
The research is focused on testing the possibilities of conventional fl exographic printing process to transfer
special conductive inorganic systems (nanoscaled Indium-Tin-Oxide / ITO) to plane glass and polymeric surfaces. Determinate parameters of the homogeneity of the transferred layers and the mean area resistance as well as the printing of defi ned structures had to be reached for the practical application (like OLED). Using a special developed proofi ng machine and the fl exoprinting proofer (Type F1 by IGT) printing tests are organized with a range of coating materials which had different fl uid properties depending on the ingredients in the dispersions. To compare the results constant viscosity of the tested fl uids and constant printing conditions have been realized. The scaling procedure of the investigated coating fl uids enabled to choose an optimal dispersion based on ITO for printing of functional layers in flexographic printing unit with conventional photopolymeric plates.

Keywords: Flexographic printing, Functional layers, Inorganic conductive layers, Nanoparticles
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Aurore Denneulin, Anne Blayo, Julien Bras, Charles Neuman

Abstract
In this work, formulation of inkjet printing inks combining the processability of the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) to the high conductivity of carbon nanotubes (CNTs) were developed. Patterns were printed on polymer films by using a piezoelectric inkjet printer. Then, morphological observations and sheet resistance measurements were made.

Electrical performances of several CNTs were evaluated (Single-walled, Di-walled, Multi-Walled, and Functionalized CNTs). Functionalized CNTs appeared to be the best candidates for printed electronics. The best configuration allows to obtain a sheet resistance of 225 Ω/sq which is very promising for many applications in printed electronics. This work also discusses the pros and cons of the different dispersion strategies developed here. The results obtained here represents an important step for the integration of CNTs in printed electronics applications and offers new opportunities to produce cost-effective electronics.

Keywords: Conductive polymers, Carbon nanotubes, Inkjet printing, Sheet Resistance
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David Bould, Tim Claypole, David Gethin

Abstract
An investigation has been performed to consider the performance of a flexographic carbon-based conductive ink, printed onto a biodegradable substrate. Although conductive carbon inks are widely used in screen printing, where controlled resistance of features is required, their use in flexographic printing represents a novel approach for producing functionality on the print. This, coupled with the use of a biodegradable substrate allows the possibilities for the production of low cost, fully disposable printed electronics. The aim of this study was to assess the performance of the carbon ink for varying anilox to plate and plate to substrate engagements. Two carbon inks were selected with different carbon to resin ratios.

The amount of carbon present in the ink was shown to affect the resistance per unit length of thinner lines. However, thicker lines, which had greater bulk, exhibited no difference between the two inks used. Anilox to plate engagement had negligible effect on the resistance of a printed line.

Keywords: Flexography, Electronics, Biodegradable
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