© 2019 The Authors. Plasma Processes and Polymers published by Wiley‐VCH Verlag GmbH & Co. KGaA Plasma Process Polym. 2020;17:e1900099 www.plasma-polymers.com | 1 of 13 https://doi.org/10.1002/ppap.201900099 Received: 8 May 2019 | Revised: 25 June 2019 | Accepted: 16 July 2019 DOI: 10.1002/ppap.201900099 FULL PAPER HelixJet: An innovative plasma source for next‐generation additive manufacturing (3D printing) Jan Schäfer 1 | Antje Quade 1 | Kerry J. Abrams 2 | Florian Sigeneger 1 | Markus M. Becker 1 | Candice Majewski 3 | Cornelia Rodenburg 2 1 Division Materials and Surfaces, Leibniz Institute for Plasma Science and Technology, Greifswald, Germany 2 Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK 3 Department of Mechanical Engineering, University of Sheffield, Sheffield, UK Correspondence Jan Schäfer, Leibniz Institute for Plasma Science and Technology, Felix‐Hausdorff‐ Str. 2, 17489 Greifswald, Germany. Email: jschaefer@inp-greifswald.de Funding information UK Research and Innovation, Grant/ Award Numbers: EP/P006566/1, EP/ N008065/1; Royal Society, Grant/Award Number: IE160969 Abstract A novel plasma source (HelixJet) for use in additive manufacturing (AM)/3D printing is proposed. The HelixJet is a capacitively coupled radio frequency plasma with a double‐helix electrode configuration that generates a surprisingly stable and homogeneous glow plasma at low flow rates of argon and its mixtures at atmospheric pressure. The HelixJet was tested on three polyamide powders usually used to produce parts by laser sintering, a powder‐based AM process, to form local deposits. The chemical composition of such plasma‐printed samples is compared with thermally produced and laser‐sintered samples with respect to differ- ences in morphology that re- sult from the different thermal cycles on several length scales. Plasma prints exhibit unique features attributable to the nonequilibrium chemistry and to the high‐speed heat exchange. KEYWORDS additive manufacturing, electron microscopy, plasma printing, polyamide, thermography 1 | INTRODUCTION In additive manufacturing (AM) free form parts are fabricated by automatic deposition of multiple consecu- tive layers of material directly from a three‐dimensional (3D) computer‐aided design (CAD) file, thus removing the need for moulds or machining. [1] The 3D‐printed structures can be obtained through different routes, classified according to the International Organization for Standardization (ISO)/American Society for Testing and Materials (ASTM) 52900:2015 as follows: binder jetting, directed energy deposition (DED), material extrusion (ME), material jetting (MJ), powder bed fusion (PBF), sheet lamination (SL), and Vat ----------------------------------------------------------------------------------------------- This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.