Greetings from Denver, home of the
Broncos, some of the most creative
suppressions of free speech since Chicago’s 1968 Democratic Convention, and the
2008 Green Photonics Forum. As one would expect, the two-day event was packed with breakthroughs in energy saving solid-state lighting and lower-cost photovoltaic technologies, but the session that was the biggest surprise for me was the session on flexible and printed circuits. Led in good part by the efforts of the
Flex Tech Consortium, the technologies to print displays and active electronic components on low-cost plastic substrates have matured over the last decade and may soon have a profound impact on how we design and manufacture many products.
Much of the early work on printed electronics was focused on displays, built on discrete substrates but new continuous printing (roll-to-roll) processes are in development. Companies like
Konarka,
Unisolar and
NanoSolar are already using various kinds of roll-to-roll technologies to produce low-cost photovoltaic panels on plastic and stainless steel substrates. Meanwhile, facilities like the
Binghamton University Center for Advanced Microelectronics Manufacturing are already assembling test beds that will use photolithographic and, in some cases, ink jet deposition of conductors, light-emitting elements, photovoltaic cells, and even active transistors on flexible polymer sheets. Meanwhile, companies like
Kovio are developing printed silicon materials that can be used to print integrated circuits, sensors and displays. Because they typically use additive processes to print the active devices, these processes can use as little as 5% of the material and energy as conventional technologies.
Today printed transistors have operating speeds measured in tens of kilohertz (or less), but that’s more than fast enough for some applications such as the driver circuitry for e-book displays or roll-printed electronic signs. The research that’s already underway to develop silicon-based inks with higher electron mobility and printing techniques that produce micron-level features should provide a 10x (or more) speed-up over the next few years. This would make it feasible to have simple microcontrollers, sensors, and other active electronics printed onto anything from a shipping label to an instruction manual.
Instead of being manufactured in a billion-dollar silicon foundry, these printed ICs could be produced in high volumes on a continuous printing system that can be built for less than 1% of the price. Quick-turn electronics printing could make it feasible for small enterprises to develop their own ASIC-like printed devices at a fraction of their silicon counterparts. Besides their significant environmental advantages, printed electronics could help cut development time and costs, and perhaps even cut production costs enough to make on-shore manufacturing practical again.
I expect we’ll even see some enterprising soul develop an inkjet-based desktop circuit printer for prototyping that costs $10 k or less and low-volume production machines for 5x to 10x more. This could give the bench top engineer the equivalent of foundry capabilities for applications which can live with the low power and frequency constraints of this emerging technology. In these applications, printed active circuit technology could do for electrical engineers what
3D printing has done for rapid prototyping in the mechanical design world. It’s even easy to imagine a hobbyist like myself knocking together a new control circuit for your
BattleBot on your PC, downloading the CAD file to a Flash drive, and bringing it down to your local
Fry’s,
Radio Shack, or
Kinko’s [Editor’s Note: now FedEx Office] for printing. I’m not sure who’s going to be selling those machines to the stores yet but I definitely want to buy some stock in them.
Comments? Questions? Make a date to have coffee with me at the
2009 Green Photonics conference in Santa Clara?
Write me at
lhg at en-genius dot net or post your comments on our blog.
