Ultrathin, Flexible Electronic Displays Could Be the New Normal in Print Media

A team of Chinese engineers has developed an updatable LCD display just barely thicker than standard paper.

A flexible, updatable e-paper.  (Image courtesy of Zhang et al., A flexible optically re-writable color liquid crystal display, 2018.)

A flexible, updatable e-paper. (Image courtesy of Zhang et al., A flexible optically re-writable color liquid crystal display, 2018.)

E-Books, Redefined?

Some recent innovations in optoelectronics have converged in a recent study that looks poised to transform print media as we know it. The study, published last week in Applied Physics Letters, seeks to integrate two young technologies: flexible displays and optically rewritable liquid crystal displays. Flexible displays have been a popular trend in consumer electronics for the past several years. Optically rewritable liquid crystal displays (ORWLCDs) allow paper-thin electronic interfaces to be updated and changed in the same way that a traditional rigid-screened electronic product would. The study’s authors set out to combine these advances into a product that could bring major change to a long-standing social institution—the morning paper. The fully realized version of this project could be a sort of e-paper that can be handled like a traditional magazine or newspaper, but also be updated in real-time.

Bringing Flexibility to ORWLCDs

There are significant challenges associated with bringing flexible display technology to traditional LCDs. However, this process is made easier with ORWLCDs. The separation of the driver and display units in ORWLCDs means that only the spacers and substrates have to flex. The display unit itself has no electronics. The development team members recognized this advantage and focused their study on developing a spacer that would keep the distribution of liquid crystal uniform when the display was bent.

The team tested three different spacer materials in an attempt to optimize the response of the LCD to physical manipulation. The one that performed best was a mesh barrier that exhibited impressive qualities when exposed to pressure. This mesh material prevented the liquid crystal from moving unevenly within the cell, allowing a high-contrast, fully visible display to be maintained when it was flexed. Scaling up the mesh spacers into a full display, the team succeeded in producing the first flexible ORWLCD.

Implications for Print Media

Flexible ORWLCDs come with a wide range of possible advantages for physically distributed publications. First, they’re cheap to produce in large quantities. The team speculated that when produced at scale, a 5-inch display might cost as little as $5. Next, they’re durable. Unlike e-readers currently available on the market, a plastic e-paper doesn’t come with a lot of parts that are likely to shatter when dropped. Finally, the optical qualities demonstrate the potential to be even better than current displays. The engineers already succeeded in displaying all three primary colors; further shrinkage of the pixels should allow for the full color spectrum in the same high-resolution, high-contrast quality that characterizes rigid LCDs. Your morning paper could soon look—and feel—a lot different.

To read about other flexible electronics components, check out A Stretchable Supercapacitor for Wearable Devices.