SCALAR

Highly Scaled Gravure Printing

Background and main goal

Gravure printing has served the graphics and art industry over decades. Here it offers two major benefits: (i) the printing resolution exceeds the resolving capability of the human eye, and (ii) the high printing speeds that can be reached. In proof-of concept studies researchers demonstrated that electro-opical devices and functional coatings can be printed as well.

In SCALAR, gravure printing will be developed further to close the gap between the laboratory scale devices and printing of devices at industrially relevant speeds. Printing of high resolution features at high speed is possible because during ink transfer the gravure cylinder is in direct contact with the substrate. This on the other side poses strong requirements to instrumentation, process parameters, gravure cylinder design and engraving method and ink. The project will push the leading role of the Swiss printer and cylinder manufacturers in the field of gravure printing.

Idea and approach

Gravure printing as such is a complex process, improvements can only be expected when looking at the interplay of printer configuration, gravure cylinder pattern and the rheological properties of the ink.

The SCALAR consortium combines the required complementary expertise to tackle this task by combining the following individual approaches:

Develop a gravure printing theory for nanoparticle and 2D materials inks gives insights for the optimization of printer, cylinder design and processing conditions.
Design a family of functional gravure printing inks (specifically nanoparticle conductors and nanocomposite inks, dielectrics, semiconductors and conductors from 2D materials) with specific rheological properties.
Develop a novel process for gravure cylinder engraving to meet the requirements of high precision printing which allows the realization of sub-micron features with freedom in cavity geometry.
Fine tune hardware and improve software of the available gravure printing unit – a high precision sheet-to-sheet printer of nsm Norbert Schläfli AG – to push the resolution and speed limit.

Demonstrators

Gravure printed grid electrodes with different line width and periodicities

Transparent micro-/nanomesh electrodes

Gravure printing will allow the production novel transparent micro-/nanomesh electrodes which can find use in large area applications. For example, in the field of e-mobility, the autonomy of electric vehicles can be increased if heating and cooling energy can be reduced by smart solar radiation management through electrochromic windows

Gravure printed circuit

Novel applications in health and environmental monitoring

Large volume printing of sensors will enable novel applications in health and environmental monitoring. Prerequisite is the miniaturization of the supporting printed circuit board. High precision printing in combination with new ink developments will allow to print embedded components (resistors, capacitors and inductances) to realize sensing systems.

Technical challenges

Currently available high throughput printing techniques can print at high speeds but are restricted to features sizes above 10 micrometers, while higher resolution techniques are limited in speed.

Thus, the key challenge for highly scaled gravure printing is two-fold: