A group of Stanford University graduate students have created an 3D printer attachment that lays down functioning circuitry right alongside the thermoplastic extruder head of an existing machine, enabling it to make functioning electronic prototypes.

"Our project enables 3D printers to deposit conductive material along with traditional plastic. The conductive material can be embedded within the 3D model and printed in the same 3D printing process," said Alex Jais, one of three students that created the print head.

The Rabbit Proto (short for prototype) 3D print head is designed to fit onto several different versions of a RepRap printer. RepRap printers are a style of machine designed to print most of their own components. For the most part, a RepRap printer can reproduce itself by extruding acrylonitrile butadiene styrene (ABS) or Polylactic acid (PLA), or other forms of thermopolymers.

The Rabbit Proto extruder head

"There are so many RepRap machines out there. This is a great way to bring this capability to other machines," Jais said.

The Rabbit Proto attachment enables designers and makers to speed up their prototyping and ideation process, going from computer design to interactive prototype with a click of a mouse.

A past prototype of the Rabbit Proto created parts of conductive circuits embedded within puzzle pieces. As the puzzle pieces were connected, a functioning circuit was created.

Rabbit Proto is an open source project. The printer head attachment is a syringe with a 1.37 millimeter nozzle that dispenses conductive ink -- up to 10cc's at a time. So far, the machine has used silver-filled silicone, but the engineers are now working with Bare Conductive, a company that makes conductive inks out of graphite paste.

Because it's an open source project, its creators are counting on outside developers to add functionality as the technology matures.

Jais created the Rabbit Proto project, along with fellow mechanical engineering student Rohan Maheshwari and Manal Dia, a juris doctorate student with a background in electrical engineering.

A demonstration of the Rabbit Proto creating a game controller, electronics and all.

The Rabbit Proto is not alone in the market of creating 3D printed circuitry. The Australia-based Cartesian Co. created the Argentum printer, a machine that sprays out conductive inks (made of silver nano particles) onto paper, fabrics, acrylic, plastics, MDF and other fiberglass substrates, creating hard and flexible circuit boards that can even be woven into clothing.

The Kickstarter effort for the Argentum printer exceeded it's $30,000 goal by $137,000. The device will be available in September for $1,599.

The Rabbit Proto project's creators were originally going to seek funding and other help from Stanford's StartX, non-profit organization whose mission is to accelerate the development of the school's top entrepreneurs.

But then the student engineers created a working prototype whose final designs were "98% complete", and decided instead to create a start-up company once they graduate this summer.

The students are already allowing users to pre-order the print heads, which are expected to begin shipping at the beginning of the summer. The technology ranges in price from $350 for a syringe that rests beside an existing 3D printer head; $450 for a print head that replaces the one on your 3D printer to extrude both thermopolymer and conductive paste, and $2,499 for a fully assembled 3D printer that includes the Super Rabbit Extruder head.

Lucas Mearian covers consumer data storage, consumerization of IT, mobile device management, renewable energy, telematics/car tech and entertainment tech for Computerworld. Follow Lucas on Twitter at @lucasmearian or subscribe to Lucas's RSS feed . His e-mail address is lmearian@computerworld.com.

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