3D Printed Electromagnetics

[rrumpf]

Here is a link to a short radio interview I did on the topic of 3D printed electromagnetics. It would be great to hear everyone's thoughts on this subject.

**broken link removed**

 

[BigBoss]

We need more technical information about 3D printed EM systems.Because it's hard to understand your Texas accent for a person who hasn't a native English speaker..-))

 

[rrumpf]

Funny. Sorry! Here is a link to my research website:

**broken link removed**

 

[biff44]

can you be a little more specific on the actual equipment you use for printing? What would be a good lower cost "entry level" 3D printer that could be used either with waveguides, antennas, or even microstrip like structures?

 

[PlanarMetamaterials]

While 3D printed metamaterials sounds fascinating, my immediate thought goes to the resolution of the system. True metamaterials (i.e. sub-wavelength periodic structures) at higher frequencies (say, X-band) may require some feature sizes on the order of tens of microns in order to be effective - are structures on this scale realistic in the foreseeable future of 3D printing?

 

[D.A.(Tony)Stewart]

Stripline is 3D in a sense. Have you discovered any fractal 3D geometries that are worth printing for improved directivity.

Although interesting, the content was fairly bland in the presentation.

The lightning bolt test sounds like an avalanche effect resonator with exotic materials for low loss. THe plastic loss tangent is key.
silver paste is expensive

Any ferrite 3D structures worth investigating or just TM wave Stripline designs?

How about a Tetrahedral Antenna? or dodecahedron omnidirectional wide band antenna?

1GW at RF for how long before the plastic melts? The problem with 3D dielectrics is the Rthermal is high due to volume/surface ratio but advantage is smaller geometry.

Any Proof of concepts?

I have good contacts for R&D on laminate molded hot pressed dielectrics using organic and plastic materials with a 10 ton press in a garage and experts on fabrication technology. but more for mechanical and thermal properties than RF.

I would imagine a big quality issue is voids in the dielectric and diffusion of conductive particles between layers of dielectric, necessitating UV cured resins for fast curing without heat.

 

[biff44]

so I guess not many are doing the 3d print thing, and those that are are not willing to share their info.

 

[rrumpf]

The structures you mention are metal so you would need to look at a metal printer. That is still quite expensive today, although Dr. Peter Kim at the University of Texas at El Paso is working on some printers that would only be a few $100 that can form very nice metallic structures. It is still developmental. Do you have a metallization process? You could purchase a 3D printer that prints plastic and coat it with metal. That has been done with stereolithography, but could be done with other processes as well. Stereolithography produces the smoothest surfaces, but I think in some applications the surface roughness is tolerable.

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For most 3D printers, resolution is submillimeter, although most systems claim a bit better than 100 microns. There are microstereolithography systems and direct laser writing systems with resolution less than 1 micron.

The resolution you mention on the threshold of what printers are doing today. Unfortunately, there is a big push for lower cost printers so there is less drive to push resolution limits.

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It was certainly a short interview, but it has gotten folks talking about this sort of thing.

We have not looked at fractal antenna geometries. It is definately possible, but we have not looked into it yet.

The high power stuff was nothing exotic. It was made my machining specially designed grooves into standard dielectrics sold by Emerson and Cuming, now Laird Technologies. They were monolithic and survived operating at over 2.0 GW peak power. It was pulsed power so thermal was not a problem.

We have some proof of concepts you can read about here: http://emlab.utep.edu

Diffusion of metal particles was not a problem for us due to not using metals. The voids is potentially a big problem, but our devices tended not to concentrate the field like a traditional metallic structure would so they are a bit more tolerant to voids. Still, especially if they are 3D printed, voids is a concern.

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Plenty of groups are 3D printing now and there is a lot of information on what printers people are using. For our dielectric work, we used various machines from Stratasys. For printing circuits, we use various machines from nScrypt. There are a lot of options out there.

 

[D.A.(Tony)Stewart]

so I guess not many are doing the 3d print thing, and those that are are not willing to share their info.

I see his website has many suggested applications and photos.