Purpose

The purpose of this paper is the production of mechanical meta-material samples by rapid prototyping (RP) and replica technique for patient-specific skin graft or cranial implant applications in tissue engineering.

Design/methodology/approach

Positive moulds (patterns) were produced by stereolithography-based RP. Impression moulding method was used for the production of silicone products (skin grafts). Alginate was used as a moulding material (negative mould). Room temperature vulcanising silicone was poured into the cavity of alginate mould and then products were produced. TiO₂ powder and carbon fibres were used as reinforcement. Meta-material structured polyurethane reinforced silicone composites were also produced. Liquid components (diisocyanate and polyol) were poured into the mould and then polyurethane was produced. Then, polyurethane was immersed in the liquid silicone.

Findings

It is found that non-destructive ultrasonic test is a fast and reliable method. Meta-material-based composites show dome-shaped tensile/synclastic surface properties which are important for the skin graft and cranial implants. Increasing the amounts of cross-linking agent and TiO₂ particles increased the hardness and elastic modulus. Carbon fibre addition enhanced the elastic modulus.

Originality/value

Although there are studies on the meta-materials, there is limited study on the RP of the meta-materials for patient-specific implants (skin grafts). Auxetic surface shows perfect fit to curved surface of the skull. Although there are studies on the silicone and polyurethane composites, there is limited study on the characterisation of mechanical properties by ultrasonic tests and strain gauge analysis.

中文翻译：

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机械超材料基聚合物皮移植的快速成型与复制方法

目的

本文的目的是通过快速原型制作（RP）和复制技术生产用于组织工程中患者特定的皮肤移植或颅骨植入物的机械超材料样本。

设计/方法/方法

正面模具（图案）是通过基于立体光刻的RP生产的。压模法用于生产有机硅产品（植皮）。海藻酸盐用作模制材料（负模）。将室温硫化有机硅倒入藻酸盐模具的型腔中，然后生产产品。TiO ₂粉末和碳纤维用作增强材料。还生产了超材料结构的聚氨酯增强有机硅复合材料。将液态组分（二异氰酸酯和多元醇）倒入模具中，然后生产聚氨酯。然后，将聚氨酯浸入液体硅树脂中。

发现

发现无损超声检测是一种快速，可靠的方法。基于超材料的复合材料显示出圆顶形的拉伸/共弹性表面特性，这对于皮肤移植物和颅骨植入物很重要。交联剂和TiO ₂颗粒的量增加，硬度和弹性模量增加。碳纤维的添加提高了弹性模量。

创意/价值

尽管对超常材料进行了研究，但针对患者特定植入物（皮肤移植物）的超常材料的RP的研究有限。辅助表面显示出与头骨弯曲表面的完美契合。尽管已经对有机硅和聚氨酯复合材料进行了研究，但通过超声测试和应变仪分析对机械性能进行表征的研究却很少。