Real-time colour-changing made possible with e-ink on the BMW iX


Beyond serving as a versatile aesthetic feature for drivers, the different colour schemes generated by the E-ink can meet various functional requirements and environmental conditions while boosting the vehicle's efficiency.

Colour is an important aspect of a vehicle. It can be tough to pick the correct colour for your vehicle, but with BMW's E-ink, this may be a decision you'll no longer need to make.

This technology allows the car to toggle between three different colour schemes to suit the user's preference. They are black, grey, and white, with adjustable light and shadow reflected with microcapsules layered on the exterior. The energy-efficient E Ink technology changes the pigment of the microcapsules and will reflect different shades based on an electric field's polarity.

Spearheading efficiency


A vehicle's exterior colour contributes to its overall efficiency - there's a significant difference in the heat absorption rate of light and dark colours when exposed to sunlight.

The heating of the vehicle and passenger compartment is a result of strong sunlight, and the total thermal energy absorbed can be reduced by changing the exterior to a lighter pigment. In cooler weather, the darker outer layer will help the vehicle to absorb significantly more warmth from the environment.

A lighter-coloured surface reflects a lot more sunlight as compared to a darker tone. The air-conditioning will not have to work as hard during hot weather with a paler shade, decreasing the overall energy output of the vehicle electrical system, for more efficient energy consumption.

This is especially crucial when used in an all-electric car, as optimised energy consumption ratings mean increased range.

How does the iX Flow technology work?


This cutting-edge technology utilises an electric field to change the polarity of microcapsules. These microcapsules have the thickness of a single strand of human hair and produce white pigments when negatively charged, black pigments when positively charged.

To affix them to the complex contours of a car, BMW has built microcapsules that are built onto ePaper segments that is precisely moulded to meet the contour of the vehicle and can reflect variations of light and shadow, while following the design lines of the automobile.

BMW's laser cutting technologies guarantee high precision when producing each segment. After attaching the segments to the vehicle, it will be powered to stimulate the connected electrical field. The integrated end-product is then sealed to guarantee optimum and uniform colour reproduction during every colour change controlled by the user.

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The E Ink technology is also energy efficient on its own. As opposed to displays or projectors, electrophoretic technology doesn't require additional energy to maintain its colour state constant. Current only flows in the short-duration colour changing phase.

The E-paper segments utilise the same technology as e-reader tablets and can only reflect colours within the grayscale. Eventually, as the E Ink technology evolves, other vibrant colours may also be pigmented.

A short demo

Harnessing the electrophoretic technology made the iX excel even more at what it's already good at, efficiency. Here's a short video from BMW demonstrating the features of the colour-changing iX Flow.

This article was first published in Motorist.