Design and Manufacturing Process of 3D-Printed Metamaterial Calcaneal Plates via Scalar Field-Driven Porous Structure Fusion

To develop a metamaterial calcaneal bone plate with integrated mechanical and biofunctional properties, this study investigated its design and manufacturing methodologies. A solid calcaneal bone plate was first designed via a hybrid reverse-forward engineering approach. Subsequently, the metamaterial plate was realized through topology optimization combined with porous structure filling, utilizing scalar field-driven fusion to integrate distinct porous structures. Finally, the plate was directly fabricated by 3D printing and postprocessed. Results show the hybrid-designed solid plate exhibits favorable overall performance. For topology-optimized plates under different mass targets, maximum stress increases moderately but distributes more uniformly, while maximum displacement rises slightly yet remains small, ensuring safety and weight reduction. Plates filled with Kelvin cell and Diamond surface porous structures via scalar field-driven fusion demonstrate excellent filling effects, good pore connectivity, and smooth transitions for reliable bond strength. The plate's textured surface with raised ripples facilitates cell adhesion. Both 3D-printed calcaneal prostheses and plates feature high quality with minimal adhered material and no obvious defects. Assembly results confirm a close fit, properly positioned screw holes, and no significant conflicts, laying a solid foundation for the direct application of metamaterial calcaneal bone plates.