{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T10:00:41Z","timestamp":1775037641385,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2020,8,13]],"date-time":"2020-08-13T00:00:00Z","timestamp":1597276800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004329","name":"Javna Agencija za Raziskovalno Dejavnost RS","doi-asserted-by":"publisher","award":["P2-0263"],"award-info":[{"award-number":["P2-0263"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004329","name":"Javna Agencija za Raziskovalno Dejavnost RS","doi-asserted-by":"publisher","award":["J2-1730"],"award-info":[{"award-number":["J2-1730"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>With recent developments in additive manufacturing (AM), new possibilities for fabricating smart structures have emerged. Recently, single-process fused-filament fabrication (FFF) sensors for dynamic mechanical quantities have been presented. Sensors measuring dynamic mechanical quantities, like strain, force, and acceleration, typically require conductive filaments with a relatively high electrical resistivity. For fully embedded sensors in single-process FFF dynamic structures, the connecting electrical wires also need to be printed. In contrast to the sensors, the connecting electrical wires have to have a relatively low resistivity, which is limited by the availability of highly conductive FFF materials and FFF process conditions. This study looks at the Electrifi filament for applications in printed electrical conductors. The effect of the printing-process parameters on the electrical performance is thoroughly investigated (six parameters, &gt;40 parameter values, &gt;200 conductive samples) to find the highest conductivity of the printed conductors. In addition, conductor embedding and post-printing heating of the conductive material are researched. The experimental results helped us to understand the mechanisms of the conductive network\u2019s formation and its degradation. With the insight gained, the optimal printing strategy resulted in a resistivity that was approx. 40% lower than the nominal value of the filament. With a new insight into the electrical behavior of the conductive material, process optimizations and new design strategies can be implemented for the single-process FFF of functional smart structures.<\/jats:p>","DOI":"10.3390\/s20164542","type":"journal-article","created":{"date-parts":[[2020,8,13]],"date-time":"2020-08-13T09:23:44Z","timestamp":1597310624000},"page":"4542","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":45,"title":["Process Parameters for FFF 3D-Printed Conductors for Applications in Sensors"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6403-8233","authenticated-orcid":false,"given":"Tibor","family":"Bar\u0161i Palmi\u0107","sequence":"first","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Ljubljana, A\u0161ker\u010deva 6, 1000 Ljubljana, Slovenia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5982-8377","authenticated-orcid":false,"given":"Janko","family":"Slavi\u010d","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Ljubljana, A\u0161ker\u010deva 6, 1000 Ljubljana, Slovenia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8963-7400","authenticated-orcid":false,"given":"Miha","family":"Bolte\u017ear","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Ljubljana, A\u0161ker\u010deva 6, 1000 Ljubljana, Slovenia"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Maurizi, M., Slavi\u010d, J., Cianetti, F., Jerman, M., Valentin\u010di\u010d, J., Lebar, A., and Bolte\u017ear, M. (2019). Dynamic Measurements Using FDM 3D-Printed Embedded Strain Sensors. Sensors, 19.","DOI":"10.3390\/s19122661"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"105025","DOI":"10.1088\/1361-665X\/ab3b35","article-title":"Shape-memory actuators manufactured by dual extrusion multimaterial 3d printing of conductive and non-conductive filaments","volume":"28","author":"Micalizzi","year":"2019","journal-title":"Smart Mater. Struct."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Watschke, H., Hilbig, K., and Vietor, T. (2019). Design and Characterization of Electrically Conductive Structures Additively Manufactured by Material Extrusion. Appl. Sci., 9.","DOI":"10.3390\/app9040779"},{"key":"ref_4","first-page":"5268","article-title":"Three- Dimensional Printing of a Complete Lithium Ion Battery with Fused Filament Fabrication","volume":"1","author":"Reyes","year":"2018","journal-title":"ACS Appl. Energy Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"17489","DOI":"10.1021\/acsami.8b01786","article-title":"Functional Polymers and Nanocomposites for 3D Printing of Smart Structures and Devices","volume":"10","author":"Nadgorny","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.compscitech.2019.05.003","article-title":"Novel electrically conductive composite filaments based on Ag\/saturated polyester\/polyvinyl butyral for 3D-printing circuits","volume":"180","author":"Lei","year":"2019","journal-title":"Compos. Sci. Technol."},{"key":"ref_7","first-page":"294","article-title":"Embedded electrical tracks in 3D printed objects by fused filament fabrication of highly conductive composites","volume":"23","author":"Tan","year":"2018","journal-title":"Addit. Manuf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1700385","DOI":"10.1002\/ppsc.201700385","article-title":"Multigram Synthesis of Cu-Ag Core\u2013Shell Nanowires Enables the Production of a Highly Conductive Polymer Filament for 3D Printing Electronics","volume":"35","author":"Cruz","year":"2018","journal-title":"Part. Part. Syst. Charact."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.apmt.2017.07.001","article-title":"Electrically conductive filament for 3D-printed circuits and sensors","volume":"9","author":"Kwok","year":"2017","journal-title":"Appl. Mater. Today"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Singh, R., Sandhu, G., Penna, R., and Farina, I. (2017). Investigations for Thermal and Electrical Conductivity of ABS-Graphene Blended Prototypes. Materials, 10.","DOI":"10.3390\/ma10080881"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.synthmet.2017.01.009","article-title":"Electrically conductive nanocomposites for fused deposition modelling","volume":"226","author":"Dorigato","year":"2017","journal-title":"Synth. Met."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Xu, Y., Wu, X., Guo, X., Kong, B., Zhang, M., Qian, X., Mi, S., and Sun, W. (2017). The Boom in 3D-Printed Sensor Technology. Sensors, 17.","DOI":"10.3390\/s17051166"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Han, T., Kundu, S., Nag, A., and Xu, Y. (2019). 3D Printed Sensors for Biomedical Applications: A Review. Sensors, 19.","DOI":"10.3390\/s19071706"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1080\/01691864.2015.1095653","article-title":"New Materials and Advances in Making Electronic Skin for Interactive Robots","volume":"29","author":"Yogeswaran","year":"2015","journal-title":"Adv. Robot."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Feng, D., Kaboli, M., and Cheng, G. (2018). Active prior tactile knowledge transfer for learning tactual properties of new objects. Sensors (Switzerland), 18.","DOI":"10.3390\/s18020634"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"11035","DOI":"10.1039\/C7NR01865G","article-title":"3D printable composite dough for stretchable, ultrasensitive and body-patchable strain sensors","volume":"9","author":"Kim","year":"2017","journal-title":"Nanoscale"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1016\/j.matdes.2017.06.011","article-title":"3D printed highly elastic strain sensors of multiwalled carbon nanotube\/thermoplastic polyurethane nanocomposites","volume":"131","author":"Christ","year":"2017","journal-title":"Mater. Des."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Liu, M., Qi, Z., Yulong, Z., Yiwei, S., and Dongliang, Z. (2020). Design and Development of a Fully Printed Accelerometer with a Carbon Paste-Based Strain Gauge. Sensors, 20.","DOI":"10.3390\/s20123395"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/j.sna.2017.07.020","article-title":"3D printing of multiaxial force sensors using carbon nanotube (CNT)\/thermoplastic polyurethane (TPU) filaments","volume":"263","author":"Kim","year":"2017","journal-title":"Sens. Actuators A"},{"key":"ref_20","first-page":"101024","article-title":"Additive manufactured graphene composite Sierpinski gasket tetrahedral antenna for wideband multi-frequency applications","volume":"32","author":"Clower","year":"2020","journal-title":"Addit. Manuf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1089\/3dp.2016.0021","article-title":"Fabrication and Analysis of a Composite 3D Printed Capacitive Force Sensor","volume":"3","author":"Saari","year":"2016","journal-title":"3D Print. Addit. Manuf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1600013","DOI":"10.1002\/admt.201600013","article-title":"Application of 3D Printing for Smart Objects with Embedded Electronic Sensors and Systems","volume":"1","author":"Ota","year":"2016","journal-title":"Adv. Mater. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1007\/s00170-014-5717-7","article-title":"3D Printing multifunctionality: structures with electronics","volume":"72","author":"Espalin","year":"2014","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_24","unstructured":"(2020, March 22). Technical Data-Electrifi filament. Available online: http:\/\/www.multi3dllc.com."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1515\/teme-2016-0057","article-title":"Properties and applications of electrically conductive thermoplastics for additive manufacturing of sensors","volume":"84","author":"Hampel","year":"2017","journal-title":"Tech. Mess."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Zhang, J., Yang, B., Fu, F., You, F., Dong, X., and Dai, M. (2017). Resistivity and Its Anisotropy Characterization of 3D-Printed Acrylonitrile Butadiene Styrene Copolymer (ABS)\/Carbon Black (CB) Composites. Appl. Sci., 7.","DOI":"10.3390\/app7010020"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1108\/RPJ-01-2013-0012","article-title":"A review of melt extrusion additive manufacturing processes: I. Process design and modeling","volume":"20","author":"Turner","year":"2014","journal-title":"Rapid Prototyp. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2017\/6913835","article-title":"Dielectric Properties of 3D Printed Polylactic Acid","volume":"2017","author":"Dichtl","year":"2017","journal-title":"Adv. Mater. Sci. Eng."},{"key":"ref_29","unstructured":"(2020, March 22). GitHub: Laboratory for Dynamics of Machines and Structures (LADISK). Available online: https:\/\/github.com\/ladisk\/papers."},{"key":"ref_30","unstructured":"(2020, March 22). Technical Data-3M Embossed Tin-Plated Copper Foil Tape 1345. Available online: https:\/\/multimedia.3m.com\/mws\/media\/37386O\/3m-embossed-tin-plated-copper-foil-tape-1345.pdf."},{"key":"ref_31","unstructured":"(2020, March 22). Technical Data-Electrolube Silver Conductive Paint. Available online: https:\/\/electrolube.com\/product\/scpsilver-conductive-paint\/."},{"key":"ref_32","first-page":"156","article-title":"3D printing electronic components and circuits with conductive thermoplastic filament","volume":"18","author":"Flowers","year":"2017","journal-title":"Addit. Manuf."},{"key":"ref_33","unstructured":"(2020, July 29). Prusa Firmware MK3. Available online: https:\/\/github.com\/prusa3d\/Prusa-Firmware."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.polymer.2011.10.063","article-title":"Establishment, morphology and properties of carbon nanotube networks in polymer melts","volume":"53","author":"Alig","year":"2012","journal-title":"Polymer"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1016\/j.jmapro.2018.08.008","article-title":"What makes a material printable? A viscoelastic model for extrusion-based 3D printing of polymers","volume":"35","author":"Duty","year":"2018","journal-title":"J. Manuf. Process."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41598-018-28744-9","article-title":"Effect of temperature on the oxidation of Cu nanowires and development of an easy to produce, oxidation-resistant transparent conducting electrode using a PEDOT:PSS coating","volume":"8","author":"Mardiansyah","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4626","DOI":"10.3390\/ma3094626","article-title":"Copper Nanoparticles for Printed Electronics: Routes Towards Achieving Oxidation Stability","volume":"3","author":"Magdassi","year":"2010","journal-title":"Materials"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7775","DOI":"10.1021\/acsanm.9b01819","article-title":"Solution-Processable Oxidation-Resistant Copper Nanowires Decorated with Alkyl Ligands","volume":"2","author":"Zhang","year":"2019","journal-title":"ACS Appl. Nano Mater."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/16\/4542\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:00:21Z","timestamp":1760176821000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/16\/4542"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,8,13]]},"references-count":38,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2020,8]]}},"alternative-id":["s20164542"],"URL":"https:\/\/doi.org\/10.3390\/s20164542","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,8,13]]}}}