Tech Explained: Flexible displays

A number of major electronics companies are working to develop a screen that is bendable – how are they doing it? Find out more in our latest Tech Explained.

For decades, displays have been made up of flat pieces of glass or plastic. The flat screen not only breaks and cracks but it dictated the shape of display technology like phones and TVs. Recently, however, engineers have begun developing bendable displays. So how do these work, and what do they mean for the future?

Traditional liquid crystal display screens (LCDs) use light emitting diodes (LEDs). These are made up of a sandwich of two types of semi-conducting material, one rich in electrons, and one poor in electrons. When electricity is passed across the semi-conductor sandwich, electrons flow from the side rich in electrons to the side that is poor in electrons. As electrons cross the junction, they pass through holes in the other side and release surplus energy in the form of light.

More recently, however, engineers have developed a new type of LED. This uses small organic molecules (OLED), or larger molecules called polymers, deposited on glass. A basic OLED is made up of six layers: two layers of protective glass or plastic on the top (the seal) and bottom (the substrate), a negative terminal, a positive terminal and two layers of organic molecules. As the organic molecule layers are thinner than the semi-conductors used in ordinary LEDs, the OLEDs are a lot thinner, lighter and more flexible. They are also brighter and need no backlight, so they use less energy. In addition, they respond much faster than traditional displays and produce truer colours. Most importantly, some types of OLEDs can be printed onto plastic to create a flexible display.

Earlier this year, Samsung announced that it had developed a flexible OLED display panel with an ‘unbreakable’ substrate and seal. According to Samsung, the bendable display passed a durability test that is based on U.S. military standards. Repeated drops from up to six feet caused no damage to the display.

But a bendable display could have advantages far beyond being break-resistant. In the future, it might be possible to make phones or tablets that can roll or fold up to fit in a pocket. Of course, before this can happen, all of the batteries and other rigid internal circuitry also needs to be made bendable. Some of this is already in development. For example, electronic manufacturer LG is working on creating battery packs that can curve, squeeze and contort like a pretzel. Other manufacturers are working on developing laptops that use a flexible screen with a rigid computer.

A bendable display could also make phones easier to carry. Lenovo developed a prototype smartwatch the size of a phone that wrapped around the wrist. Cars could also benefit from bendable screens to create digital dashboards. There are also a host of uses for display screen that can bend and fold. The displays could be incorporated into furniture, appliances, or wearables, such as this clothing and jewellery recently covered here at Springwise. The screens could then connect to a device via Bluetooth to provide a portable large-screen display whenever and wherever it is needed.