At CES this week, BMW showed the BMW iX Flow concept featuring E Ink, which it says offers the prospect of a future technology that uses digitisation to also adapt the exterior of a vehicle to different situations and individual wishes.

The surface of the BMW iX Flow featuring E Ink can vary its shade according to the driver’s preference.

The fluid colour changes are made possible by a specially developed body wrap. When stimulated by electrical signals, the electrophoretic technology brings different colour pigments to the surface.

BMW claims the E Ink technology opens completely new ways of changing the vehicle’s appearance in line with the driver’s aesthetic preferences, the environmental conditions or even functional requirements. It says the technology offers unprecedented potential for personalisation in exterior design as well as the possibility of a new form of personalisation both on the outside and in the inside of future production vehicles.

“This gives the driver the freedom to express different facets of their personality or even their enjoyment of change outwardly, and to redefine this each time they sit into their car,” says Stella Clarke, Head of Project for the BMW iX Flow featuring E Ink. “Similar to fashion or the status ads on social media channels, the vehicle then becomes an expression of different moods and circumstances in daily life.”

Electrophoretic colouring is based on a technology developed by E Ink that is most well-known from the displays used in e-readers. The surface coating of the BMW iX Flow featuring E Ink contains many millions of microcapsules, with a diameter equivalent to the thickness of a human hair. Each of these microcapsules contains negatively charged white pigments and positively charged black pigments. Depending on the chosen setting, stimulation by means of an electrical field causes either the white or the black pigments to collect at the surface of the microcapsule, giving the car body the desired shade.

Achieving this effect on a vehicle body involves the application of many precisely fitted e-paper segments. Generative design processes are implemented to ensure the segments reflect the characteristic contours of the vehicle and the resulting variations in light and shadow. The generative design algorithms enable the necessary formability and flexibility required to tailor the ePaper exactly to the design lines of the vehicle.

BMW says laser cutting technologies guarantee high precision in generating each segment. After the segments are applied and the power supply for stimulating the electrical field is connected, the entire body is warmed and sealed to guarantee optimum and uniform colour reproduction during every colour change.