Mechanical damage in porcine dermis: Micro-mechanical model and experimental characterization

Area of Science:

• Biomechanics
• Materials Science
• Biomedical Engineering

Background:

• Porcine skin is a key animal model for human skin biomechanics.
• Existing research often focuses on elastic responses, neglecting damage and energy dissipation crucial for drug delivery.
• Microstructure-driven modeling of dissipative mechanisms in skin remains a gap.

Purpose of the Study:

• To characterize the mechanical behavior of porcine skin under large deformations, focusing on damage and stiffness degradation.
• To investigate differences in biomechanics between belly and breast skin regions and their orientation.
• To develop and validate a micro-mechanics model for predicting skin deformation and damage.

Main Methods:

• Mechanical testing of porcine skin from belly and breast regions at various orientations and stretch levels.
• Imaging of collagen structure to correlate with mechanical properties.
• Development of a micro-mechanics modeling framework to simulate elastic and damage responses.

Main Results:

• Porcine belly skin exhibits greater stiffness than breast skin, characterized by a J-shaped stress-stretch response.
• No significant anisotropic properties were found in either anatomical location.
• Damage accumulation and stiffness degradation were observed, indicating energy dissipation, which the microstructure model successfully captured.

Conclusions:

• The study provides critical data on porcine skin biomechanics, including damage and softening under supra-physiological loads.
• The developed micro-mechanics model accurately predicts skin behavior and can be informed by imaging data.
• Findings are valuable for predictive simulations in designing devices for subcutaneous drug delivery.