Shear linear behavior of brain tissue over a large frequency range.

Area of Science:

• Biomechanics
• Materials Science
• Neuroscience

Background:

• Existing brain tissue shear property data is inconsistent, especially at high frequencies relevant to impact injuries.
• There's a significant need for comprehensive data on brain tissue's linear mechanical properties.

Purpose of the Study:

• To clarify and expand the linear material characterization of brain tissue.
• To provide new data on brain tissue's response at small strains and high frequencies.

Main Methods:

• Oscillatory shear experiments were conducted on porcine white matter samples.
• A custom-designed oscillatory shear testing device was utilized.
• Results were validated using a standard rheometer and compared in the time domain.

Main Results:

• Storage modulus (G') increased from 2.1 kPa to 16.8 kPa and loss modulus (G'') from 0.4 kPa to 18.7 kPa across frequencies of 0.1 to 6310 Hz at 37°C.
• Relaxation modulus (G(t)) decreased from 24.4 kPa to 1.0 kPa between 10⁻⁵ s and 270 s.

Conclusions:

• The study provides crucial new data on the dynamic shear properties of brain tissue.
• This research enhances understanding of brain tissue mechanics under dynamic loading conditions relevant to impacts.