The medical industry relies heavily on single-use plastic devices such as syringes, which contribute significantly to plastic waste streams. This research investigates a sustainable recycling pathway in which syringes are reprocessed as feedstock for additive manufacturing, creating a closed-loop system for medical plastics. Our approach centers on repurposing a low-cost Ender 3 printer (~$200) into a custom direct ink writing (DIW) platform, a technology traditionally limited by high costs exceeding $10,000. Hardware modifications include the integration of a liquid handling module for controlled fluid deposition and the addition of a UV curing chamber for in situ crosslinking. On the software side, we are developing a Python-based control architecture that communicates with an Arduino microcontroller, enabling precise regulation of extrusion rate, flow volume, and curing synchronization. By coupling hardware retrofitting with open-source software, this system provides a low-cost, adaptable platform for syringe recycling and advanced DIW applications. Beyond reducing plastic waste, this work demonstrates how accessible engineering solutions can expand the availability of specialized additive manufacturing technologies.
