These smart windows would employ phosphorescent organic light-emitting devices and would be able to switch rapidly from being a transparent window to a solid-state light source. In addition to the convenience of windows that automatically become opaque at night, the polymer LED technology has huge environmental gains, because it is far more efficient than today's energy-saving bulbs.
Will plastic transistors always be restricted to niche applications or will there be a day when plastics will take over the world? I asked Nano ePrint's Scott White what he thought:
"The general market view, which I would agree with, is that this is very unlikely. There's the challenge of performance, although this is continually being improved by new semiconductor materials. In addition, there is a significant challenge regarding density and yield. At Nano ePrint, we believe that we have a technology that allows printed electronics to dramatically improve on all three of these parameters; but even so, the practical reality is that so many billions of dollars have been invested into silicon technology and infrastructure that it's unlikely to be worth trying to change the basis of the entire industry."
This is an interesting comment in the light of the fact that Nano ePrint have demonstrated printed transistors that compare favourably with conventional electronics in both performance and footprint. However, this isn't an all plastic transistor, even though the circuitry is printed onto a plastic substrate. Instead, Nano ePrint's technology can be applied to printing inorganic semiconductor devices onto plastic.
The advantage of low-cost manufacturing remains, as does that of flexibility, but the major drawbacks of plastic circuits are eliminated. Market forces might mean that it's a long time, if ever, before this sort of circuit replaces silicon chips, but it opens up some exciting possibilities, as Scott White commented.
"Because of the massive fab and design costs for traditional silicon, the historical model has relied on general-purpose processors that can achieve extremely high sales volumes in order to effectively offset the high up-front capital cost. Printed electronics potentially allow much faster and more frequent design changes, and hence more customised designs that remain cost effective even at medium-to-low volumes."
Professor Joseph Jacobsen of MIT's Media Lab has an even more enticing vision of the future, as predicted in an MIT-published article named Print Your Next PC. By putting a "fab on every desktop", individuals could download the design of a chip like they download software today. This could transform hardware design in much the same way that the open-source movement changed software engineering."
According to Jacobsen "You could download the chip design from the web, tie in some modifications, and boom – out comes the device".
First published in PC Plus, Issue 275