Redwood City, Calif.-based EoPlex Technologies has found a low-cost way to make small, complex parts, and it plans to use the new technology for energy efficient and energy generating products.

EoPlex's process makes components using custom printing equipment and proprietary "inks."

The three dimensional parts are printed in layers using the special inks, with the ability to use multiple materials, including ceramic, metals and polymers, in the same structures.

EoPlex just pulled in an additional $4 million for its C round of funding, which now stands at $12 million. The company announced its initial Series C funding of $8 million last February.

ATA Ventures led the expanded round, with return investors Draper Fisher Jurvetson, Labrador Ventures and Draper-Richards also participating.

EoPlex's ink is what makes the process work.

"It's the secret sauce," Arthur Chait, CEO of EoPlex, told Cleantech.com. "And it truly is a secret sauce. It looks like sauce, kind of like thick sauce, and it's got multiple ingredients. There's a lot of trade secrets there."

The new cash will go toward the company's first full-scale production facility, which will put that secret sauce to the test, printing out EoPlex's first commercial product—high tech antennas for cell phones.

EoPlex plans to combine the multiple antennas needed in today's cell phones, including the main antenna as well as GPS, Bluetooth and WiFi, into one, tiny, monolithic part.

The company could soon be powering those cell phones as well, as it plans to next make parts for fuel cells and small energy harvesters, which would generate energy from the vibration of an engine or the rotation of a tire.

Take a look at some printed parts here >>

The new plant is expected to be in production by the fourth quarter of this year, but more plants are likely to follow, with the fuel cells due to hit the market next year.

Chait said his company is working with a consortium of the OEM, the manufacturer of the catalyst, and the supplier of the casing and the circuitry on that product.

"One of the things holding fuel cells back," said Chait, "is the ability to make small, intricate ceramic-metal parts."

Those parts are needed for reforming, where the hydrogen is split out of the alcohol-water mixture to fuel the system. Chait said another hurdle is micro-pumps, which have no moving parts.

"Both of those technologies require a lot of small, complex ceramic and metal constructions. Little monolithic parts that have no moving assemblies, but can do all these chemical and pumping actions."

"We can build those cheaply," said Chait.

Inexpensive fuel cells could be a boon to first responders, who currently have to carry extra battery packs into emergency situations.

"In Hurricane Katrina, carloads of spare batteries were shipped into the disaster area. People were carrying 20, 30, 40 pounds. In the military they carry sixty pounds of batteries. And they have to bring them back."

Unfortunately, Chait said many of the batteries used in Katrina were only going one way, with over-burdened workers unable to return all of the used battery packs.

EoPlex's methanol reformer will be able to convert methanol to hydrogen in a lightweight package.

"That's a chemical plant. Normally a chemically plant about the size of your desk. And we've shrunk it down to the size of a couple of poker chips," said Chait.

"It's 300 layers, 33 different features inside of it, five different materials, metals, catalysts, ceramics," he said. "Chambers, mixing chambers, pipes, valves. All miniaturized and made in one step."

In the company's production process, a "negative" ink is used as a sacrificial material that burns away to create cavities, holes, and channels or whatever shapes are required.

Next up for EoPlex are energy harvesting tire sensors, which would be installed in each tire, that can beam information back to a car's computer, warning the driver when the pressure is low.

"The problem is how do you get power into a rotating tire?" said Chait.

Using batteries leads to the danger of the warning system not working when the battery wears out, and to the environmental hazard of using disposable batteries.

EoPlex's system uses a tiny springboard, a little tuning fork, made out of a ceramic called PZT, which is a piezoelectric.

"The little vibrating tuning fork," said Chait, "will generate a charge. The charge is collected in a capacitor."

When it reaches the time for the unit to send a signal, "it draws on that power that's been accumulated in that capacitor and sends the signal."

"It's a tiny bit of power, but since you can accumulate it over many seconds, you can store up enough to send the signal. And since there's no battery involved, it lasts forever. Lasts the life of the car."

Chait said the energy harvesting tire sensors, which could also be adapted for monitoring equipment in factories, are about three years away from production due to the lead time needed in the auto industry.