3D Printed Antenna Knowledge Base

Since I'm getting more involved with communal WiFi mash networks and open source smart city project in my town, I decided to research and make a small knowledge base on 3d printed antennas.
This post will be updated as I gather new information.

Basically, there are two main areas of 3d printed antenna development: High-tech industrial and DIY. The main difference is in type of machines and purpose. Industrial 3d printers are very diverse with applications ranging from aerospace to consumer electronics, while DIY printers use mostly FDM and are used in hobby projects, drones, HAM etc.

High-tech industrial and commercial 3D printed antennas 

Optomec Aerosol Jet Antenna 3D printing

Optomec is an industry leader and they integrate their antennas in wide variety of products.



Here is the summary from process homepage:

Mobile device antennas including LTE, NFC, GPS, Wifi, WLAN, and BT have been printed using the Aerosol Jet process and independently tested by a leading cell phone component supplier.

Measured antenna performance is comparable to other production methods. The Aerosol Jet printing process is scalable – antennas can be printed on up to 4 cases simultaneously on a single machine. Machine throughput for a typical antenna pattern measuring ~300 mm2 averages 30,000 units per week. 

The Aerosol Jet printer lower manufacturing costs for antennas used in mobile devices. The process works with standard injection molded plastics – no special additives or coatings are required. Based on Aerosol Jet technology, the digital process prints conformal antennas using conductive nanoparticle silver inks.

The printing process accurately controls the location, geometry and thickness of the deposit and produces a smooth mirror-like surface finish to insure optimum antenna performance. No plating or environmentally harmful materials are used in the process.

You can see more on Optomec homepage:
http://www.optomec.com/additive-manufacturing/printed-electronics/aerosol-jet-core-applications/printed-antennas/

3D Printing antennas on curved surfaces with nanomaterials

From the source:

“Omnidirectional printing of metallic nanoparticle inks offers an attractive alternative for meeting the demanding form factors of 3D electrically small antennas (ESAs),” stated Jennifer A. Lewis, the Hans Thurnauer Professor of Materials Science and Engineering and director of the Frederick Seitz Materials Research Laboratory at Illinois.

“To our knowledge, this is the first demonstration of 3D printed antennas on curvilinear surfaces,” Lewis stated. The research findings and fabrication methods developed by Bernhard, Lewis, and their colleagues are featured in the cover article,"Illinois Calling" of the March 18 issue of Advanced Materials (“Conformal Printing of Electrically Small Antennas on Three-Dimensional Surfaces”).

Source with more details:

http://engineering.illinois.edu/news/article/2011-03-15-3d-printing-method-advances-electrically-small-antenna-design

http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/nanoparticles-enable-3d-printing-for-cell-phone-antennas

http://scholar.harvard.edu/files/lewisgroup/files/adams_advmat_2011.pdf

Here is a similar technology used at Lawrence Livermore National Laboratory:


Source article and more information:

https://manufacturing.llnl.gov/additive-manufacturing/designer-engineered-materials

Fractal antenna systems 

Fractal Antenna Systems is a company that has been working for some 20 years in creating specialized antennas for military and civilian sector based on fractal patterns. They recently published that they also use 3d printers to make some designs.

Company page: http://www.fractenna.com/

Here are some other works on the topic of 3d printed antennas:

Fully 3D Printed 2.4 GHz Bluetooth/Wi-Fi Antenna by Paul Deffenbaugh, Kenneth Church from The University of Texas El Paso:  

http://utminers.utep.edu/pdeffenbaugh/2_4_ghz_imaps_paul.pdf

3D PRINTED ELECTROMAGNETIC TRANSMISSION AND ELECTRONIC STRUCTURES FABRICATED ON A SINGLE PLATFORM USING ADVANCED PROCESS INTEGRATION TECHNIQUES PAUL ISAAC DEFFENBAUGH, M.S.E.E. Department of Electrical and Computer Engineering (doctoral dissertation)

http://emlab.utep.edu/pdfs/Deffenbaugh_PhD_Dissertation.pdf

COMPACT FORM FITTING SMALL ANTENNAS USING THREEDIMENSIONAL RAPID PROTOTYPING by Bryan Jon Willis

http://content.lib.utah.edu/utils/getfile/collection/etd3/id/660/filename/697.pdf

Origami antennas and packaging using 3D printing technologies by John Kimionis and Manos Tentzeris

http://spie.org/x113138.xml

From other media:

http://3dprintingindustry.com/2015/01/13/voxel8-3d-print-antenna-arrays-government-sponsor/

3D printed satellite and space based antennas

I made a more detailed post here with several projects and materiel sources: 

http://diy3dprinting.blogspot.com/2012/12/3d-printed-satellites.html

DIY 3D printed antennas

 

If you search Thingiverse you will currently find 500+ projects tagged with "antenna".

http://www.thingiverse.com/search/page:1?q=antenna&sa=

As far as I know all of them are arrays where the actual antenna is some form of non-printed metal wire held by 3d printed frame or enclosure.

DVB-T antenna deigned to hold metal wire on 3d printed frame and that can be mounted on a back of a TV screen

There are many models ranging from UHF satellite communication arrays to drone piloting antennas like this one:




You can also make supports and guides to make more complex antenna designs like this DIY clover leaf antenna guide:

All the files and instructions:

http://www.thingiverse.com/thing:1082803

http://flitetest.com/articles/Cloverleaf_Antenna


So can we produce real metal antennas on DIY machines? In theory there are two project that enable you to embed wire into your plastic filament:

Slew ring wire embedding:

http://diy3dprinting.blogspot.com/2014/05/3d-printing-with-guided-slew-ring-wire.html

and Spoolhead:

http://diy3dprinting.blogspot.com/2013/09/embedding-metal-wire-in-3d-printed.html

Future will show are there any projects working with conductive filaments, but I don't know anybody currently developing antennas based on them.

Services like Shapeways can print in metal (they actualy make molds and then cast metal AFAIK) so Shapeways list 300+ products tagged with "antenna".

Link: http://www.shapeways.com/search?q=antenna

Here is an example of Shapeways made antenna:

Right Hand Polarized Antenna 5.8GHz 3D - for RG316

Let me know if you have anything related to this subject. Any feedback is welcome. 

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Presentation on design of 3D printed mathematical art by Henry Segerman

If you are mathematics geek, love advanced geometry, four dimensional space, fractals, knots and art you will enjoy this presentation. One hour worth watching of Henry Segerman from Oklahoma State University giving presentation on design of 3D printed mathematical art during Symposium on Computational Geometry 2014.




The presentation in PDF format can be found here:

https://www.math.okstate.edu/~segerman/talks/design_of_3d_printed_math_art.pdf

You can see Henrys four dimensional puzzles in action here:

http://diy3dprinting.blogspot.com/2012/11/3d-printing-4th-dimension.html

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Arup develops 3d printed steel elements for heavy construction

Arup developed 3d printed steel part 

Traditional steel element of same purpose

 From the source:

Using the latest 3D printing techniques, or more accurately, ‘additive manufacturing’ – the Arup team has produced a design method for critical structural steel elements for use in complex projects.

The work signals a whole new direction for the use of additive manufacturing in the field of construction and engineering. The research also shows that additive manufacturing has the potential to reduce costs, cut waste and slash the carbon footprint of the construction sector.
We created a redesign of a steel node for a light weight structure using additive manufacturing. Arup has a lot of experience with these kind of structures, for example the tensegrity structure of the Kurilpa Bridge in Australia. The complex geometry of these kind of nodes are an ideal showcase of the possibilities of this new technique.
"By using additive manufacturing we can create lots of complex individually designed pieces far more efficiently. This has tremendous implications for reducing costs and cutting waste. But most importantly, this approach potentially enables a very sophisticated design, without the need to simplify the design in a later stage to lower costs.”– Salomé Galjaard, Team Leader, Arup

A traditionally produced steel node is at the moment still cheaper to produce, but it is expected that this will change in the short term.

Source:

http://www.arup.com/News/2014_06_June/05_June_Construction_steelwork_makes_3D_printing_premiere.aspx

If you have some doubts and want to see more about high strength optimized 3d printed structures, take a look at:

http://diy3dprinting.blogspot.com/2012/11/fractal-3d-printing-for-ultra-high.html

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Topolabs developing non-layered 3d printing software

Current FDM 3d printers print in layers which comes with certain limitations and aesthetics.  Topolabs is developing software that will enable 3d printing freed from constrains of layered printhead paths. Filament will travel in more organic shapes in all 3 dimensions. It will also enable more curved graphical and decorative surface elements printed directly on the object.


TopoLabs initial software suite will include:

• Strength Designer: By printing 3D paths instead of flat layers, you can easily orient the "grain" to your part's inherent shape. Woodworkers have aligned the grain to the task for thousands of years. Now your printer can too. 
• Flexible Part Designer: Easily create flexible, fabric-like structures. Many products that would typically be made of thick canvas, nylon fabric or leather can now be 3D printed directly in engineering polymers. With some of the new elastomer and advanced material filaments available the possibilities are endless. 
• Aesthetics & Line Art: start with any sketch or photo and your printer can create beautiful line art on 2D and 3D surfaces of parts. Think of it like embroidery or 3D graphics you can apply to many types of surfaces. 
• Layer Locking for even more strength: When you do need flat layers, lock them together. Topolabs layer locking tools interconnect adjacent layers using transverse rays to eliminate cleavage planes so your parts won't split. Finally really useful parts in all three directions.

http://www.topolabs.com/

Here is an example of different technology how more organic fractal algorithms can decrease wight and increase the strength of 3d printed object:

http://diy3dprinting.blogspot.com/2012/11/fractal-3d-printing-for-ultra-high.html

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Fractal 3D printing for ultra high model strengths

Some scientist on several European research institutions have developed a method using fractal design to produce low weight and ultra high strength objects.

Yong Mao of the University of Nottingham, UK and colleagues have developed a theoretical framework for building structures where the optimal hierarchical order of the structure depends on the load it needs to withstand. Using this technique, the team constructed such a structure – a simple frame – from a polymeric resin, using a “rapid prototyping technique” – which is an advanced form of 3D printing.

For the first element in their structure, Mao and colleagues simply construct a hollow beam, which they refer to as the “generation-0” element. Different values of thickness and radii of the beam are considered, so that the strongest beam can be built, with the least amount of material. The robustness of this beam is then tested by applying a load along its length and along its axis, to see if it fails across either. “We do this to analyse the failure modes at each local level, so that the structure is not unnecessarily strong at each level…we optimize for what properties are necessary,” says Mao. He explains this further by saying that if a 50 kg table balanced on hollow steel legs it would be about 10 times lighter than one with solid steel legs and just as robust.

Generation-3 element could be ten thousand times lighter then an original with the same strength.
One problem is that the structure has to be very precise and without flaws. Any imperfection could lead to serous defects.

“Even a small imperfection at a local scale could have a large impact as there is no extra material that could take the added stress and maybe that is why this kind of fabrication has not been practical to date,” explains Mao, who says that the team is also studying its models to better allow for such errors. But he is convinced that commercial techniques will improve over the coming year, providing the necessary precision tools. Mao also feels that the recently commercialized technique of 3D printing could really benefit the fabrication of these structures. “We could just upload our deferent designs to a program and people could download and print off the structures at home,” he says.

This is MAJOR discovery and push foreward for 3D printing and additive manufacturing! Let's hope it will be implemented soon in some practical solutions.

Source and more information:
http://physicsworld.com/cws/article/news/2012/nov/27/ultralight-fractal-structures-could-bear-heavy-loads

Research paper (you have to be registered to download):
http://prl.aps.org/abstract/PRL/v109/i20/e204301

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