Co-axial multi-material extrusion (CAMME) 3D printing

Abstract

Thermoplastic polymers are often used for fiber extrusion-based additive manufacturing. Yet, such polymers are not widely used for industrial products due to their inherently low mechanical properties, such as toughness and stiffness. Therefore, various multi-material 3D printers have been developed to resolve this problem, yet weak material adhesion leads to failure at the interface. Here, a multi-material 3D printer with co-axial extrusion capability is developed and its various benefits are explored. First, strong hydrogen-bonded interface of co-axially extruded thermoplastic polymers allows manufacturing of products with superior material properties such as toughness or stiffness. Second, the relationship between multi-material 3D printers’ sequential, Janus, and co-axial extrusion methods and polymer fracture behavior is explored. Lastly, promising applications of the co-axial multi-material extrusion 3D printer, such as a novel soft actuator and meta-material with programmable mechanical resistance are manufactured.