Development of a co-axial tri-extruder for low-melting point metals and UV-curable resins.

The need for flexible and stretchable electronics has recently gained high focus. Many fields, such as medicine, textiles, and aerospace, require conductive elements that can be mounted or sewed to the part. This means that this conductive element must have high flexibility and resistance to deformation. This research presents a novel fabrication technique of flexible electronics using coaxial extrusion methods for applications such as wearables, biosensors, and soft robotics. Another aspect of the study is the combination of eutectic gallium-indium, Acrylated Aliphatic Urethane Elastomer Resin, and Field's metal to develop flexible and multi-functional electronic devices. This work used comprehensive material properties, such as their flowability, UV curability, and flexibility, and interactions to analyze the rheological behaviors of these materials under different extrusion conditions. These materials were precisely and simultaneously deposited onto flexible substrates using a custom-designed coaxial extrusion system, while using G-code for controlling the extrusion parameters. The findings verify the feasibility of this approach in the fabrication of functional flexible conductive wires. This coaxial extrusion process has proven to be a promising technique owing to its versatility and scalability for rapid prototyping and large-scale production, hence offering enormous advancement in flexible electronics. Supplementary Information: The online version contains supplementary material available at 10.1007/s44347-025-00021-9.