Impact Indentation for Assessing the Mechanical Properties of a Mouse Brain Tissue

Take a thick mouse brain tissue slice secured to the sample holder. Place an immersion chamber over the holder and fill it with carbon dioxide-independent media to maintain tissue hydration.

Mount the holder onto the calibrated instrumented nanoindenter's stage.

Align the immersion chamber so the spherical probe attached to the pendulum arm is directly

above the chamber.

Raise the chamber until the probe is submerged in the media and aligned with the tissue surface.

Bring the probe into contact with the tissue surface, then retract slightly to allow free pendulum motion and ensure precise force application.

Begin the nanoindentation experiment, where the pendulum swings forward and strikes the tissue. This impact penetrates the surface and initiates an oscillatory motion due to damped

harmonic behavior.

Measure the pendulum displacement and the velocity to assess penetration depth, energy dissipation, and damping. These measurements reveal the tissue's mechanical properties, such as stiffness and elasticity.

When the impact indentation setup is fully complete, aspirate the medium and dry the brain slice. Then use a thin layer of cyanoacrylate adhesive to secure the sliced brain to the alum