Twenty-five hundred years ago the ancient Greeks figured out the world isn’t flat. It seems ever since then we’ve been consumed with putting our curve findings not only in our world but in our electronic devices, too.
A British firm has made gains in the development of a flexible display that soon may be curvable or wrapable. Think Dick Tracy’s watch. Not the display, but the transistor itself. In fact, the technology can be integrated not just into wearables, but also into mobile devices, car interiors, digital signage and other applications, as well. But that’s a ways off, for now.
FlexEnable, a Cambridge-based technology provider, recently created a proof of concept for its flexible organic liquid crystal displays (OLCD) technology, a flexible display curved into a smartwatch form factor. The technology has proved commercially, and the company is working with partners, including display manufacturers, to bring it to the market for applications that use full color screens that can be folded, rolled and flexed.
Technology allows electronics to be manufactured on flexible plastic film, the thickness of a sheet of paper. It combines stable, high performance organic thin-film transistors (OTFT) with passive elements to create flexible and cost-effective electronics over large and small surfaces.
Flexible devices can be fabricated to be very thin and can be manipulated to occupy a smaller space compared to rigid devices. In fact, because they provide engineers with more freedom in terms of space allocation, flexible printed circuits are gaining in popularity and their market is growing much faster compared with conventional printed circuit boards. They can be used to connect parts that move relative to each other (e.g., a laptop PC screen and the keyboard), and they can be bent, twisted, or rolled to optimize component arrangement in the end-product.
IMPORTANCE OF FLEXIBLE DEVICES AND R2R PROCESSES
The company’s foray into developing thin, lightweight and bendable devices represent the growing interest in the technology, according to BCC Research analyst Margareth Gagliardi. Flexible devices are being created with the same functionalities as traditional (rigid) integrated circuits, yet are produced with low-cost materials and processes with the intent to make them commercially available at lower unit prices than their rigid counterparts.
As flexible devices become more popular, the need for high-volume processes for their fabrication increases, she says. Consequently, the industry is steadily transitioning to the integration of roll-to-roll (R2R) technologies for the fabrication of these devices. The need to produce advanced devices on a large scale with high throughput, low cost, and high quality, while at the same time using fabrication methods that are environmentally friendly and energy efficient is also leading to the rapid expansion of the printed electronics market.
WHAT ARE R2R TECHNOLOGIES?
R2R technologies are those processes that are used to coat or create patterns on flexible substrates (such as paper, plastic, fabrics, or metal foils) in a continuous mode, while the substrate travels between two or more spinning rolls or spools.
R2R processes are also finding new fields of application in the fabrication of other devices in which lightweight, portability, and conformality are requested. Paper-thin advertising banners and flexible displays that can be embedded into clothing are just two examples of devices that are being developed and manufactured using R2R technologies. In addition to electronic and optoelectronic devices, R2R processes are also being applied in the fabrication of products for the energy and healthcare sectors, and in the manufacturing of flexible sensors.
Flexible electronics also are opening the way to the fabrication of wearable devices that can be integrated into fabrics or can be worn in contact with the skin. These devices can provide electronic (such as FlexEnables prototype), sensing (disposable medical sensors or implantable sensors that conform to organs), display (smart clothes), or energy management (phototherapy devices or wearable energy harvesting devices) functionality.
New products can be created with a faster development cycle. Thanks to the availability of many lab-scale processes, flexible devices can be prototyped, evaluated, and modified in a relatively short time — shortening the path from R&D to commercialization.
FlexEnable’s prototype uses plastic transistors to achieve its flexibility, creating what the company calls OLCD (organic liquid crystal display) screens. These achieve the same resolutions as regular LCD using the same amount of power, the company says, but these transistors can be wrapped around just about anything. FlexEnable also introduced thin flexible fingerprint sensors, suggesting they could be wrapped about a door handle.
Indro Mukerjee, chairman of FlexEnable says, "This display represents a fundamental breakthrough proving that FlexEnable's OTFT technology can be combined with mainstream OLED manufacturing infrastructures to create the most flexible and cost-effective AMOLED display.”
What’s the wait time until an AMOLED display hit the consumer market? Eighteen months is the optimistic guess, James Vincent reports.
The global market for flexible devices manufactured by R2R technologies totalled $14.6 billion in 2015 and is expected to reach $28.1 billion by 2020, reflecting a five-year compound annual growth rate (CAGR) of 13.9%, according to Gagliardi.