Does the PolyJet Printing Technology Affect Mechanical Properties of 3D Printed Synthetic Tissue?

Within the medical field, there are multiple opportunities in which 3D printed anatomical models could be utilized such as physician training, surgical planning, education, and R&D testing. Because of this, it is vital to choose materials that most closely mechanically mimic the tissues that would be seen within the simulated model. Stratasys currently has a line of Digital Anatomy (DA) printers that contain predetermined compositions and mixtures called anatomical presets to mimic soft tissue materials such as liver, myocardium, aortic, and epicardium tissue. Different compositions of these printed materials have been previously printed on the J750 Digital Anatomy printer and have undergone mechanical testing. Stratasys is releasing a new printer called J5 Digital Anatomy printer that will also have the capabilities of printing anatomical presets. To compare any differences between the two printer sample types, these mechanical tests were repeated on the J5 DA printer. Mechanical testing included stiffness testing of printed liver samples, compliance testing of printed myocardium samples, and lubricity testing of printed cardiac tissue samples. Stiffness of J5 DA liver and J750 DA liver samples were similar with slight variation seen in more rigid J5 DA samples; however, both printer samples still fell within the stiffness range observed in porcine liver tissue. Compliance testing showed comparable stiffness between J5 DA and J750 DA myocardium samples; however, J5 DA samples tended to be slightly less stiff making them more similar to porcine myocardium stiffness. Thinner J5 DA samples were more variable when compared to J750 DA samples; however, this was minimal variability when compared to that experienced in porcine tissue. Lubricity testing showed comparable coefficients of friction between J5 DA and J750 DA samples with the exception of Mineral oil and Dry lubricants. J5 DA cardiac samples saw smaller coefficients of friction; however, these still fell within the range of aortic and epicardium coefficients of frictions. Because of these results, it can be concluded that the J5 DA printer samples are comparable to J750 DA printer samples and are alternatives to animal tissue benchtop testing depending on the application.