- A set of new sustainable materials with enhanced electrical and optical properties has been produced within the European-funded MADRAS project and used for the development of flexible organic and large-area electronics (OLAE) products.
- These materials, including a nanocellulose substrate and inks based on silver nanowires, PEDOT and tungsten oxide, are built for an industrially scalable manufacturing methodology improving OLAE-devices durability.
- The materials developed present improvements in conductivity and transparency compared to materials currently used.
Barcelona, February 24th, 2022.- The European-funded MADRAS project has developed a set of new sustainable materials, which have been promptly processed via In-Mould Electronics (IME), to fabricate a new generation of plastronic products with enhanced properties.
These materials include a sustainable substrate and three types of advanced inks to be implemented as Transparent Conductive Electrodes (TCEs) and Hole Transport Layers (HTLs), allowing the development of devices by printing techniques with increased robustness, while reducing their cost and environmental impact.
The improvement of these materials is leading to a wider range of applications for Organic and Large Area Electronics (OLAE) products, device robustness, materials cost reduction, reduced environmental impact and high productivity rates.
The conductive and transparent nanocellulose substrate, based on cellulose nanofibrils films, is made from renewable resources, mostly wood. It has been optimised up to a transparency of 90%, which is the level needed to substitute most of the current polyester films used currently.
Gael Depres, Senior Innovation and R&D Grenoble R&D Center Manager at Fedrigoni Paper, affirms that this substrate is “a perfect replacement for plastic”, as it is “sustainable and recyclable in the same way as paper.”
On the other hand, several conductive and semiconductive inks for functional printing applications have been manufactured, including transparent and conductive inks based on silver nanowires suitable for slot die and screen printing, and inorganic semiconductive nanoinks based on tungsten oxide. These inks present improved properties in terms of stability, transmittance, conductivity and adhesion compared to inks currently in the market used for the development of flexible electronics.
Benjamin Dhuiege, Head of R&D at GenesInk, highlights the sustainability of these inks, ensuring that they are “easy to process, without any toxic component and with high-added value through customisation.”
In addition, MADRAS has also performed research on inks based on conductive polymers. An ink based on PEDOT:PSS plastic has been developed, providing higher mobility and conductivity.
The use of organic materials suitable for functional layers of printed electronic devices “is linked to the need to optimise the material,” explains Lubomir Kubac, Executive Head of the Centre for Organic Chemistry (COC).
“Organic-based materials offer a unique opportunity in terms of tuning their electronic properties to achieve suitable functionality in multilayer electronic structures,” adds Tomáš Syrový, Associate Professor at the University of Pardubice.
The innovative materials developed have been processed through In-Mould Electronics, a manufacturing approach combining the functional printing of electronics and the hybridisation of electronic components with traditional plastic transformation processes, such as thermoforming and injection.
To demonstrate the potential of the advanced inks and substrates developed, they have been implemented into a geotracking flexible tag for localisation of assets and a biometric photosensor for user identification in a platform of scooter sharing.
The MADRAS project is funded by the European Union’s Horizon 2020 programme and coordinated by the Eurecat technology centre. It involves 11 other partners from Spain (Eticas Research and Consulting, TECNOPACKAGING, UNE and the Cooltra Group), France (Genesink, Fedrigoni and Paragon ID), Denmark (infinityPV), the Netherlands (TNO) and the Czech Republic (COC and the University of Pardubice).
