PolyJet 3D Printing of Tissue Mimicking Materials: An Investigation of Characteristic Properties of 3D Printed Synthetic Tissue
Current anatomical 3D printing has been primarily used for education, training, and surgical planning purposes. This is largely due to the models being printed in materials which excel at replicating macro-level organic geometries; however, these materials have the drawback of unrealistic mechanical behavior and system properties compared to biological tissue. The new Digital Anatomy (DA) family of materials from Stratasys utilizes composite printed materials to more closely mimic mechanical
... mimic mechanical behavior of biological tissue, potentially allowing more realistic models for design evaluation. Various experimental configurations of the DA Solid Organ (SO) were quantitatively evaluated under axial loading for comparison with porcine liver in terms of stiffness. Additionally, the Structural Heart - Myocardium (Myo) formulations were quantitatively evaluated under different lubricant conditions for comparison with porcine epicardium and aorta in terms of lubricity. Finally, the Subcutaneous experimental configurations were qualitatively evaluated by clinical experts in terms of cutting, tunneling, and puncture representative of an extravascular cardiac lead implant procedure. In general, the experimental SO configurations showed promising compliance results when compared to porcine liver. In terms of stiffness, DA was either within the same range or on the lower bound of porcine tissue values. In terms of lubricity, DA (with lubricant layer) coefficient of friction was comparable with porcine epicardium and aorta. In terms of qualitative cutting, DA did not perform well for any of the formulations; however, tunneling and puncture were rated favorably for some formulations. Despite some limitations, DA feels closer to real tissue than other available 3D printed materials. Furthermore, the lower variability between sample to sample of DA allows for repeatability not provided by biological tissue. The promising results and repeatability indicate that DA material can be used to configure structures with similar characteristic mechanical properties to porcine liver, epicardium, and subcutaneous tissue, adding new value as a research tool.