3D Printing Embedded Wires & Fibers for Electronics — New FEAM 3D Printing Process Outlined in Research Paper

We seen some incredible innovations within the 3D printing space in the last couple of years. One area which presents a tremendous amount of potential is that of 3D printed electronics. Eventually we will get to a point where virtually any gadget can be 3D printed with all of its electrical components integrated within.

There are already companies like Voxel8 working on methods of printing with both thermoplastics and super conductive inks within a single process. We’ve also seen open source work being done through the RepRap initiative to embed solid metal wiring into objects during the printing process. Both these methods have shown tremendous promise, but neither is quite ready yet for everyday manufacturing.

With this said, researchers at the Department of Mechanical Engineering, Southern Methodist University in Dallas, Texas are taking a different approach via a new 3D printing process called Fiber Encapsulation Additive Manufacturing (FEAM), which they outlined in a recent paper published by Matt Saari, Bryan Cox, Edmond Richer, Paul S. Krueger, and Adam L. Cohen. The process, which could help further the printing of electronics as well as other non-electrical printing applications, relies on a method of extruding molten thermoplastic simultaneously with a fiber so that the fiber is immediately encapsulated within the printed layer.

Photographs of structures made with the FEAM process: (a) a close-up micrograph of sectioned, mounted, and polished 25.4-mm-outside diamater (O.D.) helical coil showing 10 layers of polymer and wire; (b and c) 13- and 4-mm-O.D. nickel wire helical coils, respectively; (d) a 25-mm-O.D. copper wire helical coil; and (e) a 26-mm-wide square coil with a 600 µm corner wire radius.

The FEAM process can be used for a variety of electrical applications such as the printing of wiring within an object, the printing of helical coils, and the inclusion of sensors or actuators as well as other fiber-like materials. Additionally such a process could also work with other materials which are not conductive metals, in a similar fashion as the technology currently being used by Mark Forged in their Mark One 3D printer. Layer by layer an object can be printed with a molten thermoplastic which instantly coats a fiber such as Kevlar®, carbon fiber, fiberglass, or Dyneema®. This could equate to printed objects with properties superior to those of pure thermoplastics.

“Coils can be produced along with other structures to make electromechanical devices,” explains a paper describing the FEAM printing process. “For example, a cone, frame, and flexures printed from BendLay were combined with a helical Cu/BendLay coil in a single monolithic build. The result, when mounted to a 3D-printed housing containing an NdFeB magnet and amplifier, was a functional powered loudspeaker. A modification of this design could yield a voice coil actuator.”

Researchers were also able to use this process to print out a membrane switch by laying metal wires down on subsequent layers, leaving a gap between the layers. When pressed the switch is able to turn on LEDs as the wires from adjacent layers are shorted together. A second press will then turn the LEDs off.

This new printing process still has a ways to go before it’s ready for marketable uses. Currently researchers are refining the process and have already overcome many hurdles. Initially the printer had problems printing encapsulated wires when a curve or abrupt turn is made during the print process. This is because the thermoplastic did not cool fast enough to encapsulate the wiring in time, leading to the wire leaving its intended path. Researchers were able to overcome this issue by directing cooled air immediately towards the extruded plastic once released. This quickly hardened the plastic keeping the bent wire in place.

The technology, once ready for market, should not be tremendously expensive, allowing businesses, small and large, as well as hobbyists to perhaps take advantage of these advancements, which could, in theory, lead to some rather extraordinary applications as the article on the FEAM process concludes:

“It could in principle be further extended to manufacture even more sophisticated systems—such as entire robots—by providing for automatic insertion of components and materials that are difficult or impossible to fabricate in situ, such as integrated circuits, MEMS devices, batteries, and precision mechanical components.”

As for when a printer like this will be readily available to the public, that is anyone’s guess; however, with companies like Mark Forge already pushing the limits with similar processes, my bet is we will see something sooner rather than later. Let’s hear your thoughts on this new printing method in the FEAM 3D Printing forum thread on 3DPB.com.