A s a little girl growing up in south-west France, Caroline Cassignol would pass the time watching planes fly over her family home. Every night in her hometown of Toulouse, Caroline’s mother — a teacher with a passion for astronomy — would take her out to gaze up at the stars through their family telescope. “The summer nights are very warm in Toulouse,” says Caroline. “You can spend hours on end outside, looking at the stars.” As planes from the nearby Airbus factory cut across the expansive sky, the magic of a human-made object in flight marked the start of Caroline’s lifelong fascination with materials.
Big ambitions are guided by the basics
Derived from the ancient Greek word for many parts, the scientific name for plastic is polymer. Rigid, yet easy to mold and lightweight, there’s an element of plastic in nearly everything we buy. From microchips to rocket ships, the material’s diversity is what drove Caroline to become the leading authority on it. “It’s a lot like Lego,” she explains. “It’s made of a lot of basic components — fibers and particles mixed together with a dough.” The right mixture of substances will create whatever type of plastic you need.
For the past 10 years, Caroline has been working in a group as part of the material design and manufacturing department at Siemens headquarters’ in Munich. She’s part of a team of 10 experts, ranging from chemists to material scientists and physicists. Her role is twofold: the first part centers around helping develop the perfect formulation; the second part is helping people find out why a material doesn’t work like it should. Both within the company and further afield, if anyone has a problem with a product and has exhausted all avenues, Caroline and her team come to the rescue.
Instead of bypassing failure — examine it instead
“I describe myself as the Sherlock Holmes of materials,” Caroline laughs. “Because people come to me when they reach a stumbling block.” When a product fails, the manufacturer has to immediately recall it. Every second a product is off the market affects a company’s bottom line.
It’s intense work but the team needs to be meticulous in their approach. “Each form of analysis is expensive,” she says. “So we have to do everything step-by-step, constantly deciding whether it makes sense or not. We begin with a diagnostic, choosing the most suitable method to start with, and move forward meticulously — adding analysis along the way.”
Her colleagues know how delicate some materials can be so they really understand them. “My colleagues are physicists, chemists, and material scientists, and we have expertise in plastics, metals, ceramics, and minerals.”
The team spirit is vital to finding problems and Caroline says it makes all the difference. “It’s great to work with my competent colleagues,” she explains, “because they’re all experts in their field. Collaboration has added value to our work.”
Hunting for failures is a race against the clock, so the whole team brings their know-how and experience to the table to try and solve the problem. If there is an occurring problem they review it together, and they always make sure their samples are adequately protected. “These samples (sometimes unique) need to be suitably prepared, conditioned, and handled, so it’s mandatory we do a good job.”
Their analysis is relentless. “We boil things, grind things, then check for the tiniest impurities with ion chromatography,” she says. “Then we make a new version and test it all over again until we get it right.” All of these conditions have to simulate real-life situations. For example, if the team is testing a train guard, they have to be certain it works under the right conditions. “We’d make a prototype of it and pelt it with stones,” she says. “We do anything to make sure a product is up to scratch.” But despite the incredibly precise nature of their work, Caroline says the best aspect of her role is the level of freedom she’s given to find a solution.
How a love for mobility launched Caroline’s career
Understanding the finest components of any material takes years of knowledge and experience. When Caroline’s interest was first ignited by the sight of an Airbus plane, it wasn’t the act of flying that captured her imagination, it was the materials that made it possible. “I love mobility,” she says. “I love train cars and planes. I want to make them lighter and more efficient.” One of the best qualities of plastic is its weight — the lighter a product is the less energy is spent transporting it from A to B. “To develop products fit for the future,” she says, “we need them to produce less carbon dioxide emissions.”
While at school, Caroline became enamored with chemistry and physics. “I wanted to work with practical things,” she says. “High strengths and lighter compositions fascinated me, so it made sense to go down the route of material science.” Having graduated from university she undertook her PhD with Airbus, focusing on composite materials. After that, she moved to Germany to work for the Max Planck Institute for Polymer Research in Mainz and the European Synchrotron Radiation Facility in Grenoble, but it was when she began working at Siemens that she became exposed to how versatile and essential plastic is. “What’s fascinating about working for corporate technology,” she says, “is that you get to work across all divisions that have a wide product portfolio, ranging from microelectronic components to high-speed trains or wind turbine blades.”
Caroline Cassignol is a Senior Key Expert — Research Scientist — specializing in plastics in Germany. She started working at Siemens in 2010. Born in France, she currently lives in Germany. Find out more about working at Siemens.
