<p>The conventional method for measuring strain in geosynthetics typically involves contact-based devices like strain gauges. While effective for strain measurement, these gauges have several limitations when applied to large-scale structures such as slopes, embankments, and retaining walls. Issues such as delamination, sensitivity to environmental factors, and limited flexibility can hinder their performance in geotechnical applications. To address these challenges and develop self-sensing geosynthetics, conductive fillers are introduced to enhance material conductivity, resulting in smart-sensing geosynthetics. In this study, test samples of conductive high-density polyethylene (HDPE) were produced through additive manufacturing, specifically 3D printing, which allows for unique design flexibility and rapid prototyping. The study first investigated the rheological properties of conductive HDPE composites to identify an optimal range for 3D printability. Subsequently, 1.75 mm filaments were fabricated, achieving a smooth surface finish along with favorable mechanical and electrical properties suitable for use in standard 3D printers. The tensile strength of the printed conductive HDPE was compared to that of standard HDPE, and the study also assessed the material’s tensoresistive capabilities. These advancements in the development of conductive HDPE not only address the limitations of traditional strain measurement methods but also enhance the functionality and sustainability of geosynthetic applications in engineering projects.</p>