Quantifying the mechanical properties of human skin to optimise future microneedle device design

Comput Methods Biomech Biomed Engin. 2012;15(1):73-82. doi: 10.1080/10255842.2011.596481. Epub 2011 Jul 12.

Abstract

Microneedle devices are a promising minimally invasive means of delivering drugs/vaccines across or into the skin. However, there is currently a diversity of microneedle designs and application methods that have, primarily, been intuitively developed by the research community. To enable the rational design of optimised microneedle devices, a greater understanding of human skin biomechanics under small deformations is required. This study aims to develop a representative stratified model of human skin, informed by in vivo data. A multilayer finite element model incorporating the epidermis, dermis and hypodermis was established. This was correlated with a series of in-vivo indentation measurements, and the Ogden material coefficients were optimised using a material parameter extraction algorithm. The finite element simulation was subsequently used to model microneedle application to human skin before penetration and was validated by comparing these predictions with the in-vivo measurements. Our model has provided an excellent tool to predict micron-scale human skin deformation in vivo and is currently being used to inform optimised microneedle designs.

MeSH terms

  • Compressive Strength / physiology
  • Computer-Aided Design*
  • Elastic Modulus / physiology
  • Equipment Design
  • Finite Element Analysis
  • Hardness / physiology
  • Humans
  • Materials Testing / methods*
  • Microinjections / instrumentation*
  • Microinjections / methods*
  • Models, Biological*
  • Needles*
  • Skin Physiological Phenomena*
  • Tensile Strength / physiology