B. How e-paper works​ :

E-paper (also called ePaper) is an electronic display technology that mimics the appearance of paper. Using the same inks as the traditional printing industry, e-paper displays (EPDs) have tiny capsules filled with charged ink particles. When the proper charge is applied, an EPD creates highly detailed images with the contrast ratio and readability of printed material.

Ultra-low power displays open new options for IoT

As a bistable display technology, e-paper is an extremely low power option. Once an EPD renders text and images, no power is needed to maintain the display. In fact, e-paper can use harvested energy to make updates, enabling you to design RFID or NFC IoT devices with battery-less EPDs

C. Structure Diagram:

The screen is flexible, and the oled screen can also be made of a flexible array material, allowing it to be closer to a fully rounded phone. Because of this, the current smartphone frame to do more and more narrow. The screen also has the advantage of power saving and screen display features, these two LCD screen can not do. The screen not only Narrows the bezel, but also reduces the phone's thickness because it is so thin. It's also because of its thinness that part of the fingerprint unlock problem has been solved.