Do Flexible Electronics Herald the End of Moore’s Law?

No doubt you've heard stories about the end of Moore's Law and how silicon-based technology is running out of steam. Over-hyped media reports about carbon nanotubes abound, with laboratory demonstration-scale devices sparking breathless news stories in the same way that every news report on cancer research opens with, “Could this be the cure?”

Flexible Chip image courtesy of IMS Chips

But there are some electronics applications where the fundamental properties of silicon wafers simply leave them out of the running. Flexible electronics is just such an application. Electronics built on flexible sheets as opposed to rigid silicon substrates opens a wide range of exciting consumer products. Flexible devices like tablet or phone screens could roll-up to fit neatly in your pocket, taking up only the space of a pen.

Much of the past development of flexible electronics was based upon organic or polymer materials. The active devices and integrated circuits were typically patterned through an additive printing process using the ubiquitous inkjet print head. Printable electronics presents an interesting opportunity, as substrates from plastic to paper are possible. For example, active devices like RFID tags could be printed onto shipping labels or directly onto the packages or products themselves.

Image courtesy of IMS Chips

Although a polymer film with circuits on it can bend and flex nicely, there is no comparison to the performance of the devices compared with silicon chips. As it turns out, silicon is only rigid when it is relatively thick. Most modern memory devices today are thinned to a few hundred microns. That's not enough to roll up in your pocket, but it points toward the possibilities. Silicon can be flexibile, but it needs to be very thin to be truly so.

Prof. Joachim Burghartz of the Institute for Microelectronics Stuttgart (IMS CHIPS) is a leading researcher in flexible silicon chips. In a recent IEEE Spectrum blog post , Prof. Burghartz compared today's cutting edge polymer electronics to the first Intel microprocessor:

Standard high volume wafer thinning does not offer a path to flexible silicon. An additive process is required similar to those developed at IMS.

Does flexible silicon offer the best of both worlds? Perhaps, but I wouldn't get too bent out of shape about it.

There's much more to flexible electronics. A good starting point for your learning adventure would be:

IEEE Spectrum

ChipFilm (you may need Google translate if your German is rusty)

If you have textbook money to spend, Professor Burghartz acted as editor for a collection on flexible IC technology: http://link.springer.com/book/10.1007/978-1-4419-7276-7/page/1