[图像上图] Skolkovo科学技术研究所（Skoltech）的研究人员使用功能表示建模和激光立体光刻，以制造具有复杂内部孔结构的陶瓷植入物。特色是显示出最高抗压强度的设计。信用：Pavel Odinev斯科尔科沃科学技术学院
在最新的December issue of theBulletin, the cover story focuses on the use of ceramic and glass materials in the human body, from established products such as hip and knee replacements to newer applications such as bioactive glasses to repair soft tissues.
Additive manufacturing is one emerging technique in the biomedical field to produce ceramic implants. Additive manufacturing techniques are gaining traction in many fields due to their ability to fabricate products with detailed structures that are difficult or impossible to achieve through traditional manufacturing methods.
在生物医学领域，植入物和支架的表面结构对于植入物和身体之间的成功骨整合至关重要。因此，生物医学研究人员非常有兴趣使用增材制造技术来创建植入物和脚手架的结构，这并不奇怪。
尤其是多孔生物陶瓷可能会受益于添加剂制造。多孔植入物具有增加的表面积，因此为成骨（骨形成）和血管形成（血管形成）提供了更多的机会。
然而，很难使用使用内部多孔结构的设计创建多孔生物陶瓷的传统方法, such as foaming and burnt-out additives or replica templates. Additive manufacturing techniques, which construct a product from the ground-up based on a model, would in theory provide more control over the complex internal porous structure.
使用常规的计算机辅助设计（CAD）建模来设计植入物在该领域的初步工作遇到了几个困难。一方面，传统的CAD模型将多边形用作构建模型的构建块，这限制了设计模型中基本元素相交的孔，支撑厚度和形态的变化。此外，CAD模型不允许在类似网格的植入物拓扑结构上轻松更改，因此为特定客户量身定制结构很麻烦。
In contrast to CAD modeling, function representation (FRep) modeling overcomes these modeling limitations.
FREP建模基于具有数学函数的几何表示。换句话说，FREP建模也不仅仅使用多边形建造模型，而是使用其他数学描述的3D对象，例如球体，立方体，圆柱体和其他更高复杂性的形状，从而打开了更多结构变化的门。
With just a few lines of code, these objects are iteratively combined through operations such as intersection, merging, and subtraction, resulting in complex geometric structures. Also, new parameters can be introduced into the equations and mathematical operators at every level of FRep modeling, so it is easy to tailor the structure for each customer.
FRep modeling isnot a novel method。但是，研究人员在最近的一个，“没有关于这种方法的这种方法的出版物”，研究人员在最近的一个open-access paper。
The researchers come from three context-driven meta-modeling research groups at the Skolkovo Institute of Science and Technology (Skoltech)设计，制造和材料中心（CDMM）在俄罗斯。在最近的论文中，他们使用FREP建模指导的激光立体光刻探索了多孔陶瓷植入物的设计和制造。
For this study, they focused on creating implants that could fill hole-like defects in小梁骨，一种轻质的多孔骨骼，可在整个骨架中提供结构支撑和柔韧性。
高级研究科学家Svyatoslav Chugunov和工程师Andrey Tikhonov的陶瓷添加剂制造团队开发了圆柱植入物的整体概念和设计，直径为4毫米，长9.5毫米。亚历山大·帕斯科教授，研究科学家Evgenii Maltsev和博士学位的团队。学生Dmitry Popov准备了基于FREP的模型，Alexander Safonov教授的团队使用有限元方法（FEM）对植入物的机械性能进行了数值验证。
Based on the numerical results, the researchers decided on four different types of structures for the implants, which differed based on the unit cells used to construct them, with varying thickness and length.
Eleven specimens of each type were manufactured using 3DMix alumina (Al2O3）粘贴在Ceramaker 900立体光刻打印机中，由3dceram（法国利多木）粘贴。合作伙伴医疗机构使用十个标本在实验室兔子中测试骨骼替代物质，研究人员使用其余标本进行机械测试。
机械测试表明，与其他三个样品相比，BI001标本（上图中的第一个样品）差不多三倍。特别是，其有效的抗压强度（65.1 MPa）与实际的小梁骨（〜50 MPa）相当，这使得“它是能够承受高工作载荷的有前途的骨骼替代品。”
研究人员将标本BI001的较高强度归因于单位细胞的密集堆积。另外，“ BI001样品在模型上部具有三行的接触表面，从而形成了与装载板的更大接触区域，并提供了从测试机中提供更均匀且更少的强度重新分布，”他们补充说。
In future studies, the authors plan to conduct biomedical testing of the specimens, including cytotoxicity and osteogenic studies. They also intend to develop a novel method of ceramic additive manufacturing for porous structures to help reduce green body post-processing time and improve quality of the internal regions of the printed parts, according to a Skoltechpress release。
The open-access paper, published inApplied Sciences， 是 ”Design and fabrication of complex-shaped ceramic bone implants via 3D printing based on laser stereolithography”（doi：10.3390/app10207138）。