Plasma jet printing of copper and silver antennas operating at 2.4 GHz

Abstract

Printing has emerged as a technically feasible and economically viable approach to fabricate antennas on a wide range of rigid and flexible substrates. Printing offers several advantages such as rapid prototyping, minimal number of processing steps and minimal equipment needs relative to conventional microfabrication and other antenna manufacturing techniques, versatility in the choice of substrates and low cost. Here we use a plasma-based printing approach to print self-sintered copper and silver antennas. The morphology of the printed films is continuous with nanoparticles agglomerated and fused together under the influence of the plasma. The printed antennas exhibit a reflection coefficient of about −20 dB or lower and bandwidth over 10% at a resonant frequency around 2.4 GHz. The results show the feasibility of printing high performance antennas on flexible substrates such as polyimide using plasma printing technology.

KEYWORDS:

• Printed antenna
• plasma printing
• atmospheric pressure plasma jet
• self-sintering
• copper antenna
• silver antenna

Acknowledgements

Access to NextFlex facilities by Space Foundry was provided under ‘Defense Manufacturing Community Support Program' funded by the Office of Local Defense Community Cooperation and through the California Governor’s Office of Planning and Research. The authors thank Alex Cook of NextFlex for his help with the measurements and Prof. Harish Subbaraman of Oregon State University for his critical review of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data that support the findings of this study are included within the article (and any supplementary files).

Additional information

Notes on contributors

Daniel H. Gutierrez

Daniel H. Gutierrez is Design and Process Engineer at Space Foundry. He has a BS and MS in Electrical Engineering from Stanford University. Between 2014 and 2018, he worked at NASA Ames Research Center as Project Lead and Assistant Lab Manager in the Advanced Space Science and Technology Group. His focus there was on nanomaterial synthesis, electrochemical characterization, design and trouble-shooting of high-power circuits, laser operation and 3D printing of lightweight compound circuits and batteries. Between 2019 and 2021, he worked as a contractor Operations Technician at Google X in the Engineering Division.

Ranajoy Bhattacharya

Ranajoy Bhattacharya received his PhD from Seoul National University in 2018. He is currently a post-doctoral research scientist in the department of electrical and computer engineering at Boise State University. His research interests include high frequency vacuum electron devices, high frequency nano vacuum channel transistors, thermionic and field emitter cathode, graphene field emitters, electron gun, RF measurement, magnet design, graphene synthesis, characterization and applications. He has published over 60 research articles.

Pranay Doshi

Pranay Doshi (Electromechanical Engineer) graduated from San Jose State University in 2019 with a degree in Electrical Engineering. At Space Foundry, he has been working since 2019 on product/process development and manufacturing of plasma jet printing including design and assembly of electronic subassemblies, print heads and process control hardware heads. He brings a range of hardware and software skills for his function as electromechanical engineer and systems and control engineer.

Dennis Nordlund

Dennis Nordlund is founder and CTO of Space Foundry. He received his Ph.D. in Chemical Physics from Stockholm Univ./Uppsala Univ., Sweden in 2004. He has been a staff scientist at Stanford Synchrotron Radiation Lightsource since 2010. He is responsible for the building of the plasma printers, and engineers work with him directly on that aspect. He has strong expertise in instrument development and process control. Dennis built the alpha and beta systems of the plasma printers shipped to customers. He has over 220 peer-revied journal publications.

Ram P. Gandhiraman

Ram P. Gandhiraman is founder and CEO of Space Foundry. He received his PhD in Electronics Engineering from Dublin City University, Ireland in 2007. He is the lead inventor of the plasma printing technology and has 10 patents in this field. He has extensive background in plasma physics, materials, characterization, and application development for nano and printed materials. Prior to founding Space Foundry, he was a staff scientist at Universities Space Research Association and NASA Ames Research Center. He has over 40 peer reviewed journal publications.