Mechanical characterization of brain tissue: experimental techniques, human testing considerations, and perspectives

Area of Science:

• Biomechanical Engineering
• Neuroscience
• Materials Science

Background:

• Accurate brain tissue mechanical property measurement is vital for neuroscience and clinical applications.
• Challenges exist due to the brain's complex structure and unique mechanical properties.

Purpose of the Study:

• To provide a comprehensive overview of techniques for characterizing brain tissue mechanical properties.
• To guide researchers and clinicians in selecting appropriate mechanical testing approaches.
• To support constitutive modeling of human brain tissue with a curated dataset.

Main Methods:

• Review of invasive techniques: atomic force microscopy, indentation, axial mechanical testing, oscillatory shear testing.
• Review of noninvasive techniques: magnetic resonance elastography, ultrasound elastography.
• Systematic comparison of invasive studies: sample preparation, testing conditions, parameters, and modeling strategies.

Main Results:

• Evaluation of techniques based on principles, applicability, studies, and limitations.
• Summary of human brain tissue mechanical property measurements from existing publications.
• Discussion of key factors influencing testing outcomes (e.g., sample size, location, strain rate, temperature, conditioning, post-mortem interval).

Conclusions:

• Characterizing brain tissue mechanics is essential for neurological research and biomechanical model development.
• The review synthesizes current experimental approaches, highlighting principles, applications, and limitations.
• A curated dataset and practical insights are provided to aid future brain mechanical research.