Among the most advanced applications of nanotechnology is the development of printed flexible electronic circuits (FPEs), which are expected to dominate soon in the field of electronic devices. FPEs are the evolution of conventional rigid printed circuits boards (PCBs), the latter being produced through a difficult, high cost and not so eco-friendly process. FPEs development is directly linked to the demand for advanced conductive inks that can be printed on cheap flexible substrates with standard printing techniques used in the industry (gravure, flexography) offering high quality prints at low production costs. Conductive inks have a leading and fast growing share in the ink market (expected to reach ca. 1.7 billion $ in 2026) as well as a strong socio-economic impact, as new applications, such as in technology consumer products (e.g. touch screens, e-paper, printed memories, energy devices, sensors for medical and automotive industries, smart textiles, 3D printing, etc.), are constantly emerging. The currently available conductive inks are mainly produced by the dispersion of metallic nanoparticles, conductive polymers, amorphous carbon, graphite and/or their mixtures in resins. In recent years, however, the tremendous progress in graphene research has triggered strong interest towards its application also in the field of conductive inks, exploiting its advantages (thermal/chemical stability, lower cost, bending without significant degradation of excellent conductivity) compared to the aforementioned materials. At the same time, the requirement for more environmentally friendly printing processes has led to the need for conductive water based inks. However, pure graphene is highly hydrophobic, making its direct dispersion in water systems very difficult or even impossible.
The GRAPHEIN project aims to contribute to these challenges by aiming at (a) the production of conductive water-based printing inks (not simply based on water dispersions of graphenic materials) also building on industrial knowledge and experience and (b) the development of a final product (for gravure-flexography) that can be produced in existing industrial lines of ink production, without needing to significantly modify them. In addition, a functional electronic device (e.g. antenna) as well as specialized printing test images will be designed in order to demonstrate the printing capabilities of the new inks in demanding industrial FPEs applications. Moreover the most promising (against a set of specific performance criteria) ink formulations will be upscaled and tested in industrial printing machines. The new GRAPHEIN ink technology will be evaluated on the basis of techno-economic criteria in order to explore the prospects for further exploitation of the project’s results. The successful outcome of the project is expected to lead to significant findings with multifaceted scientific, technological, economic and environmental benefits.
The new inks, apart from exhibiting high performance, are expected to be fully compatible with the existing environmental legislation, providing the basis for an eco-friendly technology that meets the demand for environmentally friendly products of high quality and added value not only for ink producers but also end-users in highly popular and commercially competitive industries such as the supply chain, smart packaging etc.
Co‐financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code:Τ1EDK-02093).