What’s taking so long for smartphone displays to be made of plastic?

The Wall Street Journal reports that Samsung is stepping up efforts to mass produce mobile device displays made of plastic rather than glass. Your smartphone might soon become, says the Journal, “unbreakable, lighter and bendable.” And we might even see these next-gen displays as soon as the first half of 2013. Samsung and others have exhibited prototypes, or proto-prototypes, of technology like this in the past (see “Are Bendable Smartphones the Future?”).

Key to flexible display technology are OLEDs (organic light-emitting diodes), which are very thin and thus can be put on flexible plastic. OLEDs and the materials they could be embedded in point towards a future where electronics don’t necessarily take the rigid shapes we associate with them today; they might even someday be “draped like cloth,” wrote Kristina Grifantini in a look at the tech last year (see “The First Fully Stretchable OLED”).

And what has taken them so long? The Journal cites “technological barriers” without going into further details (and Samsung wouldn’t officially go on the record here; the Journal cites one of those “person[s] familiar”).

The next year or so could definitely see some real innovation in the realm of device screens. Samsung isn’t the only one chasing the flexi-screen prize. (See under: Sony, LG, others.) Sharp Corp. and LG Display have already brought out LCDs using so-called “in cell” tech that makes screens thinner by embedding touch sensors right into the display.

The holy grail, though, is plastic, according to an analyst the WSJ spoke with. As Lee Seung-chul put it: “The key reason for Samsung to use plastic rather than conventional glass is to produce displays that aren’t breakable. The technology could also help lower manufacturing costs and help differentiate its products from other rivals.” It would certainly save a lot of iPhone users the expense and annoyance of buying bulky protective cases.

One wonders, incidentally, how the folks behind Gorilla Glass feel about this race for the plastic screen?

It seems fair to say that we will be more likely to see flexible plastic e-ink screens hit the mass market before we see the same thing at work in our iPhones and Droids. LG was reported to have entered mass production on flexible plastic e-ink displays back in March.