Because the entire display stack can be screen printed on a flexible plastic substrate, the 100 to 200µm-thin displays can be produced cheaply, either on a sheet-to-sheet process for small-scale and rapid prototype manufacturing or via a roll-to-roll process for large volumes.
Unlike electrophoretic displays based on e-Ink, which are truly bistable, rdot's displays are semi-stable, based on reversible redox reactions responsible for the colour changes of the electrochromic materials. After a while, the turn-on colour fades away until a short voltage pulse is applied to turn the segment to maximum contrast again. But since rdot are using proprietary material recipes and printing processes, the company is able to tune a display's bi-stability period from minutes to days for custom applications.
In the process, it can make its displays faster switching (being less stable) or slower for very low update rate applications, so can it customize the display's colours, shapes and transparency.
But lacking of true bi-stability, how can such a display compete with incumbent ePaper solutions such as those provided by E Ink? eeNews Europe candidly asked rdot's CEO Felix Karlsson.
After all, using segmented cells, every display becomes a custom solution requiring Non-Recurring Engineering (NRE) fees, wouldn’t it be simpler to use full active matrix ePaper instead?
One competitive advantage Karlsson is keen to emphasize is lower cost. "Because we do everything in a few printing steps, the manufacturing cost is certainly lower than any E Ink solutions. They need an active matrix backplane, which we don't, and this adds to the costs. Our solution is ITO-free, environmentally friendly and can be made with 100% organic materials" said Karlsson.