Renault Group and the CEA are continuing to innovate together for tomorrow's vehicles. After the novel high-efficiency bidirectional electric vehicle charger the partners announced in 2023, they are now bringing their technical expertise and creativity to in-cabin comfort.
The new architectured material—a complex mesh structure—took two years of research and testing to develop and has resulted in twelve patents. A single additive manufacturing (3D printing) step using a single material can now produce customizable, lightweight, high-performance parts offering adaptive mechanical behavior.
These innovative parts could replace seats, armrests, center consoles, and any other part traditionally made from an assembly of several materials.
A novel lattice structure
The strategically-arranged lattice structure at the heart of the innovation is made possible by breakthrough digital design tools and methods. The mesh is made up of strands that can be configured three-dimensionally to create multilayered networks of cells. Each layer can be given its own characteristics and functions.
The 3D-printed single-material monolithic parts have more complex designs than traditional parts. However, they are much simpler to produce. A single 3D printing step is all it takes. Plus, with no additional assembly steps or manufacturing waste, the technique also helps reduce parts' overall GHG emissions.
And because the parts are printed from thermoplastic polyurethane, they are recyclable. Additional research is addressing the compatibility of these new materials with bio-based and other materials.
Ultra-customized in-cabin comfort
Automotive seats are just one example of how the new materials could be used. The seat and seat back could be made much thinner, and overall weight could be reduced by around 30%. And, in terms of firmness, support, and cushioning, these single-material seats outperform the conventional seat structures, foams, and fabrics.
Seats could also be custom-manufactured for individual drivers' body types, preferences, and pressure points on the seat, with different areas offering different degrees of firmness, support, and cushioning.
Designers will also enjoy the freedom of 3D printing, which makes a vast array of shapes, textures, and other customizations possible.
The promise of additive manufacturing
Renault Group has been using 3D printing—or additive manufacturing—to make tooling parts for years now. More recently, the technique has made inroads into the car maker's prototyping processes. 3D printing is considered an additive—rather than subtractive—manufacturing technique because material is added layer by layer rather than removed. The information about the part is contained in a digital file.
The new mesh developed by Renault Group and the CEA will create opportunities to innovate in-cabin parts like steering wheels, seats, armrests, and center consoles that drivers and passengers come into contact with.
“The whole of the CEA's and Renault Group's R&D know-how is greater than the sum of its parts. This innovation is a testament to what can happen when two major innovators work together. It could position us to bring our customers an in-cabin experience they can't get anywhere else. We are still exploring the full potential of this new architectured material for increased customization, of course, and also to enhance other areas of the vehicle," said Jean-François Salessy, Senior Vice President, Vehicle Synthesis and Upstream Technology, Renault Group Engineering.
“The CEA is investing heavily in additive manufacturing, which offers almost total design freedom, shorter manufacturing lead times, and opportunities for product customization while enabling new functionalities, saving materials, and reducing weight. This latest advance with Renault Group is evidence of what cutting-edge design and characterization can do for the development of architectured materials and their integration into real-world use cases," said François Legalland, CEO, CEA-Liten.