The fabrication of multi-material medical phantoms with both patient-specificity and realistic mechanical properties is of great importance for the development of surgical planning and medical training. In this work, a 3D multi-material printing system for medical phantom manufacturing was developed. Rigid and elastomeric materials are firstly combined in such application for an accurate tactile feedback. The phantom is designed with multiple layers, where silicone ink, Thermoplastic Polyurethane (TPU), and Acrylonitrile Butadiene Styrene (ABS) were chosen as printing materials for skin, soft tissue, and bone, respectively. Then, the printed phantoms were utilized for the investigation of needle-phantom interaction by needle insertion experiments. The mechanical needle-phantom interaction was characterized by skin-soft tissue interfacial puncture force, puncture depth, and number of insertion force peaks. The experiments demonstrated that the manufacturing conditions, i.e. the silicone grease ratio, interfacial thickness and the infill rate, played effective roles in regulating mechanical needle-phantom interaction. Moreover, the influences of material properties, including interfacial thickness and ultimate stress, on needle-phantom interaction were studied by finite element simulation. Also, a patient-specific forearm phantom was printed, where the anatomical features were acquired from Computed Tomography (CT) data. This study provided a potential manufacturing method for multi-material medical phantoms with tunable mechanical properties and offered guidelines for better phantom design.

具有患者特异性和现实机械性能的多材料医学模型的制造对于外科手术计划和医学培训的发展非常重要。在这项工作中，开发了用于医学幻象制造的3D多材料打印系统。在这种应用中，首先将刚性和弹性材料结合起来以获得准确的触觉反馈。幻像设计成多层，其中分别选择了硅酮墨水，热塑性聚氨酯（TPU）和丙烯腈丁二烯苯乙烯（ABS）作为皮肤，软组织和骨骼的印刷材料。然后，将打印的体模用于通过针插入实验研究针-体相互作用。机械针-幻像相互作用的特征在于皮肤软组织的界面穿刺力，穿刺深度和插入力峰值的数量。实验表明，制造条件即硅脂比例，界面厚度和填充率，在调节机械针-幻像相互作用方面发挥了有效作用。此外，通过有限元模拟研究了材料特性，包括界面厚度和极限应力，对针-模相互作用的影响。而且，打印了患者特定的前臂幻影，其中解剖特征是从计算机断层扫描（CT）数据中获取的。这项研究为具有可调机械性能的多材料医用体模提供了一种潜在的制造方法，并为更好的体模设计提供了指导。