How Dr. Stella Clarke Pioneered the Colour-Changing Car

By Alice Duthie
on 2 October 2024

In an incredible fusion of tech and design, BMW engineer Dr. Stella Clarke has redefined automotive innovation with the creation of the first colour-changing car. In our exclusive interview with Dr. Clarke, she shares the key processes that brought her visionary concept to life. Dr. Clarke also discusses the challenges she overcame, highlights the essential role of collaboration in her work, and offers valuable advice for aspiring female engineers.

As the inventor of the first colour-changing car, can you walk us through the key steps and processes that led to this incredible innovation?

Inventor’s a strong word. I feel I just put together things that hadn’t previously been combined. But I agree that it’s incredible, and I’m super proud of what my team and I have achieved!

The first steps were pretty humble. You just have an idea, it’s in your head. Since you think it’s a pretty good idea, you start telling people, pitching it, and gaining support. I first pitched the idea in 2018, got a small sum of money, and put a small team of colleagues together. There were four of us – two designers, one UI specialist, and myself (an engineer). But that didn’t end up working out. The truth is, we all had normal jobs, and fitting in an additional hobby project really wasn’t in anyone’s agenda. So I plodded on alone for the first two years. Being someone who loves prototyping and making stuff in the local makerspace, I produced small demos. These were really simple demos that used the technology of colour change (E Ink). They weren’t “wow” demos, but they were way better than just a PowerPoint slide deck. Of course I had one of those too, and used slides and images to take people on a “journey” as to how this technology could be used on a car. Despite countless pitches, most initial feedback was rather pessimistic. So you certainly need a “don’t give up” mentality.

With time, the prototypes got better, and they got bigger. At some point, I even bought video editing into the equation and showed people videos of colour change on a car (self “CGI’d” in After Effects). 

One turning point was when we attached large E Ink panels on the side of a white BMW iX that was lying around in one of our workshops. We stuck the panels on with double-sided sticky tape, and I was sitting on the floor acting as the controller. As I touched wires together with my hands, it looked like the side of an iX was alternating between black and white. A colleague of mine happened to video this, the video ended up circulating within BMW, and essentially led to the iX Flow. We built the iX Flow as a small team of makers. It was the ultimate prototype, and essentially led to our next more advanced concept cars including colours: the BMW iVision Dee E Ink, and the BMW i5 Flow NOSTOKANA.

Quite a lengthy explanation. But I think key steps in the beginning of this journey were (1) lots of prototyping, and (2) just never giving up in the face of pessimism. In the later years, and still now, I would be remiss without mentioning the (3) very talented team building this incredible innovation. 

Dr. Stella Clarke Colour-Changing Car

What inspired you to explore the use of E Ink technology in automotive design, and how did the idea evolve into the BMW iX Flow?

It was a fascination for the technology of E Ink. It’s literally colour change. Imagine something, anything, changing colour, and that’s pretty much what the E Ink technology is or can enable. This technology has been hiding in eReaders for a long time but has so much more potential. The most amazing thing about E Ink is that it’s bistable, which means it needs no energy to remain in a certain state, or a certain colour. For an engineer, that’s like magic. It fascinated me so much that I had to do something.

Getting to the iX Flow, however, was technically very challenging. Getting this material on a car is way different to integrating it into an eReader. It involved a lot of experimentation, a lot of trial and error, a lot of failing.

What were some of the key challenges you faced in developing the colour-changing car, and how did you overcome them?

A new idea always involves convincing others to come on the journey with you, especially when there is a time and financial investment component. Once I was over that hurdle and others could see the revolutionary potential and the wow factor, the rest fell into place.  However, it’s not to say it’s an easy journey.  It never is for anyone bringing something completely new to market. 

Technically all our concept cars have been quite difficult to build. BMW has highly talented engineers who help solve this which is why the brand has always been innovative and pioneering with design and technology.

Time management was certainly also a problem. Up until the iX Flow, and even while making the iX Flow, this was all a “side hobby” alongside my normal job as an engineer. So it ate a lot into my free time. My family tried hard to be understanding. At times I’d bring my young daughter into the workshop. She’d join in while we were building and slept on a couch in the corner of the room while we built throughout the night.

Dr. Stella Clarke Colour-Changing Car

How did it feel to present the BMW iX Flow at CES 2022, and what was the significance of that moment for you as an engineer?

Absolutely surreal. We ended up making three iX Flow vehicles in four months – one test car, one backup car, and one final car. Those months were so incredibly intensive that you don’t really think much about the actual presentation of the car. We were literally still fixing things minutes before CES opened in 2022.  After the opening, it felt like a storm had suddenly subsided, and you were out there presenting to the world. One of my most memorable moments was when one of the stand workers at CES came to me in a quiet moment, showed me her feed, and said, “look, your car is going viral”. It was a pinch-me moment.

How important was internal support and collaboration within BMW in bringing the colour-changing car to life?

Absolutely vital. Among the sceptics you find the believers, and you hang on to them real good! I could never do this alone, I needed other people to believe in this too. At one point in 2020, I created a three-minute video pitch and sent it to hundreds of colleagues within BMW. Most replied saying it was a cool idea, and two people were actionable and wanted to make something with me. Big shout out to Michi Schraut and Dirk Müller-Stolz.

Dr. Stella Clarke Colour-Changing Car

How do you think this technology can evolve in the future, and what are your next steps as an engineer?

The tech will evolve a lot in the coming years. Integrating it onto any surface will get easier with time, and you’ll start seeing it more and more in everyday life. Think fashion, architecture, art, and so much more. 

Do you have any words of advice for women and girls thinking about pursuing a career in engineering?

Look into this! Find out what engineers do and see if it gets you excited! I’m a huge fan of makerspaces. I not only love the ability to prototype and build, but I relish in the “you can do it” attitude. Consider visiting a local makerspace, full of machines, prototypes and incredibly creative people. Talk to them, ask about their projects, and see if you leave with a smile on your face (spoiler: most people do).

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