What are the Challenges in Using Nano Indentation on Biological Tissues?

Biological tissues are often heterogeneous and anisotropic, meaning their properties can vary in different directions and regions. This can complicate the interpretation of nano indentation data. Additionally, tissues are typically softer and more prone to deformation than traditional engineering materials, requiring careful calibration and handling to avoid errors. Maintaining the physiological conditions of the tissue, such as hydration and temperature, is also crucial for accurate measurements.