Despite the somewhat dramatic name, so-called “flexible glass” is actually no more than ultra-thin glass that can—as the result of its thinness—be rolled up to a fairly tight diameter. Because of this property, flexible glass is a potential substitute for plastics, metals, paper, textiles and other materials that are currently being proposed to serve as flexible substrates, as well as encapsulation materials and cover glass for electronics and solar panels.
Flexible glass is currently being developed by several major glass companies; the one with the greatest “mindshare” in this space is undoubtedly Corning Inc. Other firms that are developing products in this space are SCHOTT, Nippon Electric Glass, Tokyo Electron and ASG/Asahi Glass.
At the moment, judging from corporate pronouncements, much of the development effort in the flexible glass space is being focused on creating substrates capable of roll-to-roll (R2R) processing. This is probably because R2R manufacturing is currently favored by the display and solar panel industries.
However, as Table 1 shows, the first substantial revenues for flexible glass are likely to come from lightweight display, solar and lighting panels, because this is where much of the demand for previous generations of flexible glass has come from. Weight—or, rather, the lack thereof—is obviously a major selling point for mobile displays, and glass used in displays for laptops and cell phones has continued to get thinner over the years. Lightweight solar panels are attractive for roofs whose weight-bearing capabilities are questionable, older roofs, or ones that weren’t built with heavy overlays in mind.
Over $1 billion in revenues will be spent by 2018 on flexible glass for intrinsically flexible products of various kinds (see Table 1). The intrinsically flexible product that has the most notoriety at the present time is clearly the flexible display. After many years of failing to live up to analysts’ expectations, these now look like they will begin to appear in electronics stores next year (or possibly the year after). Samsung is one major company that has promised full-scale production of flexible displays within that time period.
That said, most would-be flexible display makers are likely considering plastics and metal foils for substrates/encapsulation rather than flexible glass. After all, these materials are readily and inexpensively available. On the other hand, flexible glass, if available in sufficient volume, should be a reasonably easy sell into the flexible display market, since the transparency and strong encapsulation that flexible glass can provide are likely to be highly valued for mobile and TV displays. Display makers may therefore be willing to pay a premium for these characteristics.
For intrinsically flexible displays, the cover glass, substrate and encapsulation (to the extent that they are three separate materials) must all be flexible; plastic could provide this capability in all three cases. However, flexible glass is likely to offer more transparency and higher scratch resistance. Metal foil would make an attractive substrate, but it is not transparent so is not an option for a cover glass.
Additional Potential Applications
Although few (if any) makers of flexible glass seem to be targeting the solar panel space at the present time, a number of opportunities exist for flexible glass in this sector. The functionality advantages of flexible glass for solar panels include conformability to the building fabric and better ability to withstand high winds and other difficult weather conditions. In addition, aesthetic considerations include the ability to manufacture attractive value-added products using curved or flexible glass.
Similar claims can be made for organic light-emitting diode (OLED) panels. However, the consensus is that neither widespread use of OLED lighting nor the introduction of conformable/flexible OLED lighting is going to make it out of the lab until (at least) 2015. So far, it does not appear that anyone has seriously proposed using flexible glass for flexible/conformable OLED lighting. Indeed, flexible glass may prove to be quite expensive for this application, which is likely to be quite cost sensitive. On the other hand, OLED lighting might be an area that makers of flexible glass should consider, because it could potentially use a lot of substrate/encapsulation material.
Additional applications for flexible glass currently seem to be a long way from the strategic thinking of the flexible glass makers, but may provide some new business revenues for these firms in the future. Sensors have been suggested as possible long-term opportunities for flexible glass. These are most likely to include the touch sensors used in touch-screen displays and other large area sensors.
Flexible Glass Benefits
As the numbers in Table 1 suggest, NanoMarkets is expecting big things from flexible glass, but we also note that it is possible to be too optimistic. For one thing, as shown in Table 2, flexible glass faces competition from several more mature materials. In addition, flexible glass may be too expensive when transparency is not required. For example, copper-indium-gallium-selenide (CIGS), which remains one of the up-and-coming sectors of the solar panel industry, does not need a transparent substrate, effectively eliminating one of the advantages of using glass in such cases.
However, glass can hit its rivals in the substrate/encapsulation marketplace with performance features that will be hard for the competition to match. Glass is the most thermally stable of any of the materials considered here, and high-temperature processing can often result in higher performance of an R2R/printed electronics product. This advantage would be just as important for flexible glass as any other kind of glass. Glass is also a long-lived product, while plastics often are not able to make this claim.
Flexible glass is also likely to get better in the future. The manufacture of flexible glass has not proved easy but, in a sense, it is a task that is never quite completed since the goal is to make glass ever thinner.
The information presented in this article is based on “Markets for Flexible Glass—2011,” a recent report from NanoMarkets. For additional information, visit www.nanomarkets.net.