Improved Manufacturing Performance of Screen Printed Carbon Electrodes through Material Formulation

Abstract

Printed carbon graphite materials are the primary common component in the majority of screen printed sensors. Screen printing allows a scalable manufacturing solution, accelerating the means by which novel sensing materials can make the transition from laboratory material to commercial product. A common bottleneck in any thick film printing process is the controlled drying of the carbon paste material. A study has been undertaken which examines the interaction between material solvent, printed film conductivity and process consistency. The study illustrates that it is possible to reduce the solvent boiling point to significantly increase process productivity while maintaining process consistency. The lower boiling point solvent also has a beneficial effect on the conductivity of the film, reducing the sheet resistance. It is proposed that this is a result of greater film stressing increasing charge percolation through greater inter particle contact. Simulations of material performance and drying illustrate that a multi layered printing provides a more time efficient manufacturing method. The findings have implications for the volume manufacturing of the carbon sensor electrodes but also have implications for other applications where conductive carbon is used, such as electrical circuits and photovoltaic devices.

Scalable Production of Graphene Inks via Wet‐Jet Milling Exfoliation for Screen‐Printed Micro‐Supercapacitors

“…The latter allow the ink to be optimally transferred onto the substrates, with the ink flowing when sheared by the squeegee, and minimal spreading once printing . Furthermore, the ink diluent must be sufficiently volatile in order to facilitate the drying and curing processes of the printed device (allowing optimal process productivity, i.e., high profitability, to be achieved), retaining the ink viscosity during the printing and avoiding the so‐called “drying‐in effect” (i.e., the drying of the ink in the mesh) . In order to achieve a screen printable ink, the as‐produced WJM‐graphene was dried and re‐dispersed in a mixture of H 2 O/EtOH (70:30) and terpineol (1 wt%) (by the solvent‐exchange process) with a concentration of 75 g L −1 .…”

High-speed imaging the effect of snap-off distance and squeegee speed on the ink transfer mechanism of screen-printed carbon pastes

“…Research has been conducted to identify the effects of various press parameter settings as well as ink formulation on screen-printed carbon inks and pastes to optimize print quality and electrical performance. 1,8,9 The effect of mesh material and geometry was found to be relatively consistent for a range of inks, with finer meshes leading to reduced film thickness but improved definition, which is preferable for fine feature printing. [9][10][11] Parameters such as squeegee hardness, angle, and geometry have also been found to have consistent effects on a range of inks, where softer squeegees at shallow angles were found to produce thicker deposits.…”

Flexible Active Matrix Addressed Displays Manufactured by Screen Printing

“…Printing of electrically conducting materials is not novel in itself; materials such as carbon and silver have been deposited by printing techniques for many years, aiming at, for example, flexible electrical wires, membrane switches, and electrodes in sensor applications. [ 1 ] The major reason for the large efforts that currently are being spent within the field of printed electronics is related to the combination of such relatively simple printed electrical wires and electrodes with the novel electronic functionalities that often originate in devices based on organic (semi)conducting materials, where one primary goal is to obtain complete electronic systems by only using printing techniques in the manufacturing process. (Semi)conducting polymers are one class of materials that have been thoroughly explored, mainly due to the possibility to control the conduction state of the materials, because this allows device architectures such as diodes and transistors.…”