This comprehensive review explores the advancements in material extrusion-based 3D printing techniques for sensor fabrication, focusing on fused filament fabrication (FFF) and direct ink write (DIW) methods, also known as robocasting. The study employs a scoping review methodology to address the current state of knowledge in additive manufacturing of sensors using these two 3D printing approaches. The review covers a detailed investigation of various sensor types, challenges, sensor characteristics, and materials used in the fabrication process. The methodology involves five stages: formulating the research question, conducting a database search, establishing inclusion and exclusion criteria, extracting useful data, and discussing the findings. The review discusses 68 sensors fabricated using FFF and DIW techniques, including strain sensors, accelerometers, acoustic emission sensors, electrochemical sensors, and more. It also highlights significant challenges and limitations in both FFF and DIW-printed sensors, providing a robust resource for future research in material extrusion-based 3D printing of sensors.This comprehensive review explores the advancements in material extrusion-based 3D printing techniques for sensor fabrication, focusing on fused filament fabrication (FFF) and direct ink write (DIW) methods, also known as robocasting. The study employs a scoping review methodology to address the current state of knowledge in additive manufacturing of sensors using these two 3D printing approaches. The review covers a detailed investigation of various sensor types, challenges, sensor characteristics, and materials used in the fabrication process. The methodology involves five stages: formulating the research question, conducting a database search, establishing inclusion and exclusion criteria, extracting useful data, and discussing the findings. The review discusses 68 sensors fabricated using FFF and DIW techniques, including strain sensors, accelerometers, acoustic emission sensors, electrochemical sensors, and more. It also highlights significant challenges and limitations in both FFF and DIW-printed sensors, providing a robust resource for future research in material extrusion-based 3D printing of sensors.