A novel method for visualising and quantifying through-plane skin layer deformations.

Area of Science:

• Biomechanics
• Materials Science
• Dermatology

Background:

• Skin exhibits complex, non-linear, viscoelastic, and anisotropic material properties.
• Understanding skin deformation is crucial for applications like shaving, needle insertion, and patient repositioning.
• Large local strains can occur during these interactions.

Purpose of the Study:

• To present a novel imaging-based method for studying skin deformations and layer mechanics.
• To visualize and quantify skin layer deformations during dynamic mechanical testing.
• To establish a foundation for constitutive models in finite element analysis of skin.

Main Methods:

• Combined shear experiments with real-time video recording.
• Utilized digital image correlation and strain field analysis.
• Applied 10% global shear strain to porcine skin using a rotational rheometer and analyzed with ARAMIS software.

Main Results:

• Demonstrated inhomogeneous skin deformation with distinct strain regimes in different layers.
• Quantified shear strain: 2.0-5.0% in the epidermis and 10-22% in the dermis.
• Determined shear moduli ranging from 20 to 130kPa.

Conclusions:

• The developed imaging method effectively visualizes and quantifies skin layer deformations and mechanics.
• Results highlight significant differences in strain distribution across skin layers.
• This method provides a valuable foundation for advanced constitutive modeling of skin biomechanics.