Flexible OLED panels made a grand entrance into the display industry five years ago. The technology that makes them possible has been around for a while, but it was during the CES edition in early 2018 when big brands like Sony, Samsung, HP, Lenovo, Xiaomi, and LG unequivocally announced their plans to develop flexible devices. And in no time, some of them hit the market.
However, the only flexible component of electronic devices currently available to us, such as smartphones and televisions, is the OLED matrix. It is a significant limitation, but materials engineering is on the verge of eliminating this constraint. It is now possible to manufacture wafers of integrated circuits that comprise intrinsically flexible transistors. This changes everything.
The real deal: truly flexible devices are on the horizon.
What sets a flexible OLED panel apart from a rigid one that uses the same technology is its substrate. This element acts as a structural support for the layer of organic light-emitting diodes that make up the OLED panel. This film of diodes must be mounted on a layer that provides structural rigidity, and that is the primary role of the substrate.
Conventional rigid OLED panels use a glass substrate, which is extremely rigid and not useful for producing a flexible panel. To overcome this limitation, engineers have turned to polyamide substrates, a sophisticated type of plastic. However, the image reproduction matrix coexists with inherently rigid electronic components, making it impossible to produce entirely flexible electronic devices until now.
To achieve this, an essential component needs fine-tuning: flexible chips. Fortunately, it is now possible. Researchers from South Korean institutions, including Sungkyunkwan University, the Institute of Basic Science, the Institute of Advanced Science and Technologies, and Seoul National University, have published an intriguing article in Nature Electronics outlining their process for manufacturing an elastic polymer that can produce flexible FET transistors. These are the transistors found in most of the integrated circuits of the electronic devices we use today.
Their approach differs from those of other researchers who have attempted to develop the technology needed to produce flexible chips. Their most significant achievement is the development of a large-scale manufacturing technique for a dielectric material that enables the production of flexible electronic components that have electrical properties comparable to those of rigid electronic components of an inorganic nature. Impressive.
The dielectric material is a synthetic polymer similar to some of the plastics with which we are all familiar. Its physicochemical properties make it compatible with transistor manufacturing. To produce it, they employ vacuum deposition, a highly sophisticated process that deposits material molecule by molecule on a solid substrate.
According to the researchers, their dielectric material can be stretched 40% beyond its original volume without affecting its physicochemical properties or insulating capacity. Most impressively, their technology allows the production of flexible integrated circuit wafers that, according to their experiments, can be used in large-scale flexible chip production.
The photograph above shows one of these flexible wafers. The researchers admit that they need to improve their flexible chips’ efficiency, optimize the manufacturing process, and enhance their dielectric capacities. However, what they have accomplished has tremendous potential.
The breakthrough achieved by these South Korean scientists is a significant milestone in the development of truly flexible electronic devices. It is an exciting time for the display industry as we witness a new era of flexible electronics that will transform the way we use our devices.