take a closer look into BMW i5 Flow NOSTOKANA's color-changing technology

the technology behind the art

The BMW i5 Flow NOSTOKANA is a rolling artwork that demonstrates BMW‘s rapidly advancing color-changing technology. Harnessing E Ink technology, the concept was first proposed six years ago by Stella Clarke, Research Engineer Open Innovations at the BMW Group. Since then, a number of iterations have been unveiled. In January 2022, the entire body of an iX Flow alternated between just black and white. The next year, the i Vision Dee debuted 240 E Ink sections which could display thirty-two colors. This latest development is more advanced still, with 1,349 sections intricately composed to render the Ndebele patterns of South African artist Esther Mahlangu, the first woman to create a BMW Art Car in 1991. Following the unveiling at Frieze Los Angeles 2024, designboom took a closer look at how this electrifying homage to Esther Mahlangu’s art was created.

BMW i5 Flow NOSTOKANA | images courtesy BMW

beyond light: bmw harnesses e ink

The glimmering, color-changing effect of the BMW i5 Flow NOSTOKANA might seem like light manipulation, but Stella Clarke clarifies, ‘it’s a change of color, not light. It’s extremely low energy.’ The secret lies in E Ink, the same technology used in e-readers. Millions of tiny capsules within the film sections react to electric charges, mixing together to change their color. The ‘bistable’ nature of E Ink is key. Unlike light sources that require constant power, E Ink holds its color state even without electricity. As Clarke puts it, ‘when you take the energy away, it stays that color.‘ This means that the technology is incredible sustainable when it comes to energy usage. It requires about twenty watts during the twelve seconds for the entire body to change colors, then it requires zero energy to maintain.

While the individually-controlled film sections can display a wider color range, challenges remain. Clarke notes that the ‘refresh rate’ of E Ink is inherently quite slow, and that it would take ten seconds for an individual panel to change color. ‘We’ve tried to hide the color mixture that’s going on through clever animations, like the swipe effect,’ she explains. ‘But if you look at any one section, you will see the mixing going on.’

Engineering Meets Design

The idea for a color-changing car originated with Clarke herself: ‘it was just an idea in my head at the time,’ she says. Her original pitch deck even featured an image of Esther Mahlangu — a fitting homage to the artistic possibilities this technology held. A few years later, and Clarke’s vision has become reality. ‘Being able to work with the artist I included from the original pitch deck was so inspiring,’ she shares. The project is an exciting example of how BMW continues to work with artists to merge design and technology.

Holger Hampf, President of Designworks, a BMW Group Company, emphasizes this synergy between art and engineering. So far, the i5 Flow NOSTOKANA is a prototype, a tangible example of the technology’s potential. ‘We went a step further not only to showcase the technology… but to show an application of it,’ says Hampf. This prototype builds upon the legacy of the BMW Art Car series, a platform for artistic exploration on BMW vehicles.

the road ahead

The bigger question is, will this technology ever hit the road? According to Hampf, reliability is the always the main concern when it comes to concepts. Prototyping plays a crucial role in ironing out these issues. ‘This is the beautiful thing about prototyping, we use concept cars to push ideas further to improve them over time,’ he says. ‘The iX Flow was quite rough when it debuted at CES… you could see every single laser-cut panel. At that time it felt almost impossible to wrap E Ink, a flat surface, onto such a complicated three-dimensional form of a car.‘ The film sections have since become increasingly complex, more colorful, and are even weather resistant. Hampf notes the team’s current discussions in improving impact resistance.

One of the most surprising discoveries during development, according to Clarke, was the emotional connection people have with this technology. ‘We’ve realized this is something that people want emotionally, not practically. It’s a thing that brings joy.’ She notes that the team often fixates on the concept’s practical use cases, thinking it’s what people value. ‘But it’s the other way around. The emotional use cases bring joy and make people smile. Actually we know statistically that people want to choose the color of their racing stripes and rims (laughing). Tell me the use of that!‘ With this latest iteration of its color-changing concept, BMW recognizes that cars can have an emotional impact, more than just machines, but like works of art.