World’s first laser printer, Xerox PARC's Dover-Alto, circa 1976.
World’s first laser printer, Xerox PARC’s Dover-Alto, circa 1976.

Since Xerox researchers revolutionized putting ink on paper with the invention of the laser printer in 1969, the technology has been applied to “printing” DNA as well as 3D structures. Now the approach has a promising future in electronics manufacturing, with “ink” made from tiny fragments of silicon chips.
New York Times reporter John Markoff describes in today’s Science Times how a new technique developed at Xerox’s Palo Alto Research Center will print computing power onto a flexible surface.
Demonstrating what PARC CEO Stephen Hoover wrote for Techonomy last year—that “a lot of the opportunities we’re going to find in the ‘Internet of things’ are going to be about how to embed intelligence at very low cost in a distributed way into the world”—one potential of the technology Markoff describes is to take 3D-printing to the next level, by manufacturing not just a structure, but also its electronic functionality.
Eugene Chow, the PARC electrical engineer whose team developed the new technology,  known as “xerographic micro-assembly,” told Markoff that the “crazy new revolutionary tool” prints silicon “chiplets” onto a surface.
Markoff explains in an associated Science Times Podcast that chiplets, developed with funding from the National Science Foundation and DARPA, are electronic circuits more like grains of sand than what we now know as silicon chips. He says:

“You can get so many transistors onto a given area of silicon these days that you can put basically a computer with the power of an early IBM PC into a grain of sand … Think of these chiplets as being suspended in a fluid and then they’re put down on the surface that you want to put them on using electrostatic forces which you control so you can place them very exactly. Think of it also like a computer motherboard—the thing inside your PC where you now connect chips; well they’re connecting chips too but they’re doing it in a printing fashion rather than doing it with either machines or the hands of workers.”


Though researchers have yet to scale the technique from printing a few chiplets to hundreds on a surface, Markoff says there are a variety of interesting potential uses. He suggests being able to smear computing power out over a one-foot square surface to make a flexible device. “Think about being able to sit on your smart phone without breaking it,” he says, or about Band-Aids printed with built-in heat or motion sensors … “going for a workout … putting a patch on your skin, and then, after your workout, tearing it off and downloading your data.”
Ultimately, Markoff says that by marrying design to desktop manufacturing, xerographic micro-assembly “could enable a whole new generation of citizen entrepreneurs.”