The ELIPSE 2 project has come to an end after three years of work. Building on the ELIPSE project, it aimed to advance a breakthrough technology to a higher level of maturity: the direct printing, using conductive inkjet technology, of electrical and electronic functions such as conductive traces, shielding, antennas and mounting pads for surface-mount components onto complex, non-developable 3D parts, without additional wiring or connectors.
A key objective: making printed electronics robust and ready for industrialisation.
Integrating an electronic circuit directly onto a part, rather than adding it as a printed circuit board (PCB) substrate connected using conventional wiring, makes it possible to simplify architectures, reduce weight and assembly complexity, while paving the way for automated manufacturing. Following an initial phase that achieved Technology Readiness Levels (TRLs) 3 to 4 in materials, processes and robotics, ELIPSE 2 aimed to consolidate this foundation and integrate more demanding functions, including data transmission, signal management across a variety of substrates, more complex geometries and multilayer architectures.
Alongside the IRT, the project brought together several leading industrial partners: Airbus Atlantic, Blackleaf, Demgy and Safran Electronics & Defense.
The work focused on four scientific and technological challenges:
– designing printed electronics on 3D structures while taking thermal and electromagnetic constraints into account;
– controlling shielding and interference for radio applications;
– identifying more environmentally friendly conductive inks than silver-based inks;
– and automating printing on complex 3D parts.
A wide range of results:
- Qualified materials and a lower-impact solution identified: Of the eight conductive inks tested, two emerged as the most suitable, depending on the application: one for power applications and the other for fine conductive traces intended for low-power applications. Copper-silver hybrid inks were also developed as a more cost-effective and environmentally friendly alternative to pure silver, while maintaining electrical performance.
- Multilayer architectures validated in real-world use cases: By combining graphene ground planes, insulating layers and silver traces, the team demonstrated data transmission through a functional USB connection and validated the performance required for onboard Ethernet transmission.
- Robustness characterised under real aircraft operating conditions: The printed traces withstood exposure to common fluids, including coffee, insecticide and de-icing fluid, as well as salt spray and humidity. Thermal cycling and flexural testing campaigns made it possible to identify the most reliable configurations, the failure mechanisms to monitor, and potential ways to improve process reliability. These findings provide key insights for the next stages of industrialisation.
- A robotic system now capable of printing on doubly curved surfaces: The project developed a complete method for 3D scanning, trajectory generation and deformation compensation. This enabled the successful direct printing of an antenna onto a highly curved part, providing an initial proof of feasibility for printed electronics on complex aeronautical and aerospace parts.
- A GPS antenna meeting performance requirements: Three versions of planar inverted-F antennas (PIFAs) were designed and tested. The final version achieved a particularly promising axial ratio and a gain meeting the requirements for circularly polarised GPS reception.
- A first quantified environmental assessment: Conducted with Pôle Éco-Conception in accordance with ISO 14040 and ISO 14044, the life cycle assessment (LCA) showed that the technology has a very low environmental impact. The main priority for further reducing this impact remains the type of ink used, particularly silver-based inks. Introducing new copper-based ink formulations would offer a significant environmental advantage.
Tangible benefits for industry
Beyond its scientific results, ELIPSE 2 has delivered assets that can be directly reused. These include enhancements to Draw-it, the software developed at the IRT, with new features and a library of trajectories and patterns. These additions make it easier to generate robotic trajectories without requiring specialised robotics skills.
The equipment — a six-axis robot, a jetting printhead and a 3D scanner — together with all experimental data, will be retained at the IRT to support future projects.
Two functional demonstrators, developed with Safran Electronics & Defense and Airbus Atlantic, enabled TRL reviews to be initiated with the industrial partners, marking a key step towards integration into operational environments.
What comes next?
Building on these results, IRT Saint Exupéry now has a proven technological foundation to support the industrialisation of printed electronics on 3D parts. This is an asset for developing lighter, more integrated and more sustainable aeronautical and space architectures.