Electrical Resistivity of 3D-Printed Polymer Elements.

Area of Science:

• Materials Science
• Additive Manufacturing
• Electrical Engineering

Background:

• Fused filament fabrication (FFF) enables the creation of complex structures.
• Electrically conductive materials are increasingly integrated into 3D-printed components.
• Understanding the electrical properties of these materials is crucial for their application.

Purpose of the Study:

• To investigate the electrical resistivity of 3D-printed conductive structures at various scales.
• To analyze the influence of structural geometry and postprocessing on resistivity.
• To evaluate the piezoresistive properties and thermal stability of hybrid conductive structures.

Main Methods:

• Characterization of electrical resistivity on single tracks (traxels), monolayers, multilayers, and hybrid structures.
• Utilized two commercial conductive filaments: Proto-Pasta and Koltron G1.
• Investigated the effects of thermal postprocessing (annealing) and Joule heating.

Main Results:

• Single traxel geometry and resistivity dictate the overall electrical anisotropy and resistivity of printed bodies.
• Annealing significantly altered the resistivity of extruded fibers and traxels.
• Hybrid structures exhibited good thermal stability up to 70 °C and a notable piezoresistive response (gauge factor 15-25).

Conclusions:

• The geometry of individual printed elements is critical for controlling the electrical properties of FFF conductive structures.
• Thermal postprocessing offers a method to tune the resistivity of printed conductive materials.
• Hybrid structures demonstrate potential for applications as integrated heat elements and strain gauge sensors in stiff materials with limited elongation.