

In Silicon Valley, however, sometimes the formula gets reversed. An inventor creates something so novel that it's practically, well, useless. But that rarely stops a true innovator.

That's certainly the case at EoPlex, a Redwood City startup where a team of innovators is developing a revolutionary way to print objects in three dimensions.

Specifically, the company intends to mass-produce tiny gears and switches using a process that builds 3-D objects by layering materials on top of each other, over and over, until a third dimension takes shape. Think of a book instead of a poster.

At EoPlex's offices, where a prototype assembly line is already printing metal and ceramic parts the size of a dime, chief executive Arthur Chait admitted he had one question when he heard about the invention: "What is it good for?"

Of course, that was a few years ago and since then Chait, a manufacturing expert who has built components for customers like Cisco Systems, has raised about $13 million and created four prototypes. So he has a fair idea where EoPlex is headed.

"This technology is perfect for manufacturing parts that are the size of your thumbnail and are hard to make," he said.

EoPlex backer Warren Packard with the Draper Fisher Jurvetson venture capital firm allowed that it is an unusual investment.

"At least when we started, it was a solution looking for a problem," he said.

Now the company is poised to serve a new industrial market -- mass-producing tough, tiny 3-D components far more complex than anything that can be made today.

"Few people, in fact none, have put together the manufacturing technology to build component parts like they can," said Michael Ehlert, president of the International Microelectronics and Packaging Society, the engineering group that builds the circuit cards and other physical structures needed to make finished electronic devices.

How? Chait said the essence of the invention is the "ink" in its presses, a substance so exotic that the company has chosen not to file a patent, but rather to protect it as a trade secret.

"It's like the Coke formula," Chait said. "It's absolutely a secret sauce."

To the naked eye, EoPlex's "secret sauce" has the look and consistency of toothpaste. Chait said this gooey paste is laced with powdery particles of ceramics or metals. The paste is the carrier; its powdery cargo ultimately forms the finished object. Most importantly, this carrier paste has the astonishing ability to evaporate and disappear when heated, leaving behind only the ceramic or metal that it initially carried in powdery form.

EoPlex uses this remarkable fluid to "print" 3-D metal or ceramic shapes in much the same way that a printer makes a book -- by printing one sheet at a time, and laying each new sheet over its predecessor.

There is, however, a key difference between a book and the sorts of objects that EoPlex prints. A book is solid. But thanks to its magical ink, EoPlex can print shapes that have interior voids -- such as a metal box.

Here's how:

Imagine that the first pass of "ink" squirts out a square line that contains a metallic powder. This square blob is immediately hardened by a quick blast of ultraviolet light. Then the EoPlex technology prints a second layer of fluid inside and around the four hardened lines.

This second fluid differs from the first. It does not have any metals inside. It has one purpose -- to create a flat surface upon which to print the next layer.

Thus, to build a box of any given height involves a repetition of these steps: lay down the next square layer of metal-bearing paste; harden it with ultraviolet light; fill and surround it with the next layer of empty goo; harden it up; and repeat until done.

In the final step the printed object is placed in an industrial furnace, where the real magic occurs. The goo, the ink, the carrier fluid evaporate completely -- leaving behind only the metal or ceramic that was deposited in those alternating steps.

"I'm not aware of anybody who is doing what they're doing," said Ehlert, the outside expert.

To put this technology to work, Chait has targeted applications in which the finished 3-D article is too small to make by conventional means.

For instance, EoPlex is developing a device to be built into the tread of a tire. The device is designed to generate voltage through the process of piezoelectricity -- the ability of crystalline substances such as quartz to create an electric charge simply by being vibrated -- in this case by the pressure on the tire as the rubber hits the road.

EoPlex designed the piezoelectric gadget to replace a traditional battery. Why would a tire need a built-in battery?

As Chait explained, after the Firestone/Bridgestone tire scandal of 2000 Congress passed a law that, among other things, requires that new cars be equipped with tire-pressure sensors capable of sending a signal to the car's dashboard -- like the low-oil light -- should the tire be low on air.

EoPlex is betting that its solid-state piezoelectric generator will prove cheaper to make and more durable in operation than the batteries tiremakers use today.

"There's a lot of tires made each year," Chait said.

Venture capitalist Sean Foote of Labrador Ventures, which provided some of the earliest funding for EoPlex, said early-stage investors aren't necessarily troubled if there's an initial fuzziness about the market for an invention, so long as they're convinced that a company's management has the contacts and experience to match the technology with some need.

Foote said two things were clear when Labrador led the 2004 venture round that put $4.3 million into EoPlex: The ever-shrinking size of electronic devices would create a demand for new ways to make small components, and that Chait was the perfect guy to find its proper use in manufacturing. Just before joining EoPlex, he had been senior vice president for Solectron, the Silicon Valley company that has spent 30 years making components for companies like Cisco, Hewlett-Packard, Sun Microsystems and other high-tech brands.

"Art (Chait) had incredible contacts in the manufacturing community," Foote said.

Of course, there remains the mystery of how this process came to be invented. Suffice to say that back in the late 1980s and early 1990s, inventor and entrepreneur Chuck Taylor came up with some of the basic insights while he was working for medical device companies in Silicon Valley.

Taylor, 52, is hardly a household name but he's a familiar type. A college dropout like Steve Jobs or Bill Gates, Taylor spent much of the 1980s and 1990s inventing little gizmos for the medical devices industry -- the companies that make catheters and other gear for things like minimally invasive surgery.

One of his inventions was a way to hold a heart still during bypass surgery -- an innovation that he helped build into a company called CardioThoracic Systems. When it was sold in 1999, Taylor said he ended up "with a nice nest egg" -- and the free time to develop this printing technology, which had turned out not to be useful in making medical devices, but which had captured his fancy nevertheless.

"I'd pick up bird skulls and think, 'We could make this, with all the interior space,' " he said.

He got serious about the project in 2001. Acquaintances introduced him to Chait in 2002. Things took off from there as Chait started asking his old manufacturing customers for ideas about how this technology might help them build components.

Today, EoPlex has dreams of printing out gazillions of tiny 3-D parts. Chait says he has some firm prospects -- but no announced contracts.

So while the end of the EoPlex story is unknown, the pattern is familiar: the idea that won't die; the team that's willing to give it a go; the investors willing to fund them.

"They're betting they can make things that you couldn't do with traditional manufacturing," veteran technology observer Paul Saffo said.