How PCA helped an aerospace client master ultra-thin coatings
A project carried out with Safran Electronics & Defense
At Safran, every detail counts. Whether in aircraft engines or defense systems, performance often depends on characteristics that cannot be seen with the naked eye. This is the case of coatings only a few microns thick, which play a crucial role in the durability and efficiency of components.
And this is precisely where one of the big questions of materials engineering comes in: how do you precisely control the thickness and structure of these ultra-thin deposits on parts with complex shapes?
The challenge: from the laboratory to the factory
Since 2025, PCA (Physique-Chimie Avenir) has been collaborating with Safran Electronics & Defense on a fascinating problem: optimizing the deposition of titanium dioxide (TiO₂) on glass substrates and, above all, qualifying it on large parts with curved geometries. At first glance, this may seem very specialized. But in reality, it is a question many manufacturers ask themselves: how do you go from a process that works well in the laboratory to stable, reliable production under real conditions?
The new study carried out by PCA explores exactly that. The goal? Control the thickness of the TiO₂ coating, improve its adhesion to the substrate, and precisely control its morphology – notably the formation of cracks whose geometry must remain perfectly predictable. Nothing less.
Four phases for an industrial qualification
The project is broken down into four well-thought-out stages, each answering a precise question.
Phase 1: optimization of the TiO₂ concentration and plasma cleaning starts with optimizing the formulation. First, a TiO₂ concentration must be synthesized that allows a deposit of controlled thickness, then plasma cleaning is set up to improve adhesion. Next comes the critical check: the cracks formed must be less than 20 micrometers wide and spaced about 200 micrometers apart. This is the kind of specification that demands great rigor.
Phase 2: comparative study of concentrations and lift-off literature review builds on the results. On one side, a detailed literature search on “lift-off” techniques (the process used to transfer the pattern). On the other, the synthesis of three new TiO₂ concentrations to observe how thickness varies with the formulation, while maintaining a morphology consistent with the criteria defined in phase 1.
Phase 3: deposition on an industrial part and process qualification comes when PCA applies the process to a real industrial part supplied by Safran – large and with a curved geometry. This move from the simple model to the complex component is often the moment when theory meets practice. This is where we find out whether the process is truly robust or needs adjustments.
Phase 4: documentation and presentation of the results closes the project. An exhaustive report brings together all the results, methods, protocols and interpretations. A videoconference presentation with the client completes this deliverable.
“Every micrometer counts.”
Why it matters
Beyond Safran’s specific case, this study illustrates a crucial reality: materials engineering demands both creativity and flawless discipline. Every micrometer counts. Every variable – concentration, deposition time, prior cleaning – influences the final result.
For a company like Safran, active in aerospace, space and defense, this reliability is not an option. It is a requirement. TiO₂ coatings make it possible to create functional patterns or protect surfaces. But only if they behave exactly as planned, under the right conditions, on real parts.
PCA in action: from theory to industry
This is exactly what sets a Junior Enterprise like PCA apart. With 42 years of existence, PCA has built up the expertise of engineering students trained to the highest scientific standards, working in the laboratories of ESPCI Paris-PSL, a school renowned for its 10 joint research units and its 6 Nobel Prizes. But PCA doesn’t stay locked in the labs: it is committed to turning this knowledge into concrete solutions for industry.
This collaboration with Safran is the proof. In 14 weeks, PCA commits to delivering not only rigorous scientific results, but also a qualification of the process on real industrial parts. It is the bridge between research and production.
Conclusion: when precision meets innovation
The optimization of ultra-thin coatings for aerospace is never finished. But this PCA-Safran study shows how, by combining scientific rigor, state-of-the-art equipment and educational commitment, we can progress toward an ever finer mastery of processes.
And that is what innovation in industry is all about: what seems invisible at first glance, but makes all the difference when it comes to performance and reliability.
