8. Comparison of Porcine Brain Tissue with Potential Surrogate Materials Under Quasi-static Compression and Dynamic Mechanical Analysis

Computational models and physical surrogates can provide important insight into complex biomechanical loadings, such as those leading to mild Traumatic Brain Injury (mTBI). However, accurate material properties are required in order to fully realize the potential of such models. This study compares the material properties of porcine brain tissue with various surrogate materials (0.4%, 0.6%, 0.8% concentration agarose gelatin; 3%, 5%, 10% concentration bovine ballistic gelatin; and Sylgard 527). The quasi-static compression properties and dynamic viscoelastic properties (1–200 Hz) for each material were measured using a Dynamic Mechanical Analyzer (TA Instruments, DMA Q800). The tests were performed at room temperature, using fresh porcine brain tissue samples (less than 15 min post-mortem) obtained from a local abattoir. The quasi-static compression stress-strain curves of 5% concentration was in good agreement with the experimental data, while the remaining tissue surrogates were generally higher in stiffness. In terms of dynamic analysis, the complex modulus of the agar and Sylgard 527 materials were found to be comparable to the porcine brain tissue, while the bovine gelatin diverged at higher frequencies.