Finite Element Analysis of Skin Deformation and Puncture for Microneedle Array Design

Area of Science:

• Biomedical Engineering
• Computational Mechanics
• Dermal Science

Background:

• Limited understanding of microneedle insertion mechanics, focusing on device failure rather than skin interaction.
• Previous research overlooked skin deformation, puncture dynamics, and tip positioning under full microneedle arrays.

Purpose of the Study:

• To develop a numerical approach for evaluating skin deformation and puncture conditions in full microneedle array designs.
• To create a design framework for optimizing microneedle parameters based on performance outputs.
• To assess the impact of patient and anatomical variability on microneedle performance.

Main Methods:

• Finite element submodels calibrated using traction-separation laws for microneedle-epidermal interface properties.
• Validation of a single microneedle model with experimental data and nanoindentation.
• Implementation of validated models into a 3D finite element analysis for full microneedle arrays.

Main Results:

• Quantification of skin deformation, force to puncture, and penetration depth for microneedle arrays.
• Detailed analysis of the punctured state at each microneedle tip.
• Evaluation of design variables (shape, material, spacing) and patient parameters (tissue thickness) on insertion outcomes.

Conclusions:

• The developed numerical framework enables comprehensive analysis of microneedle array insertion mechanics.
• The study provides insights into optimizing microneedle design by considering both device and patient factors.
• This approach facilitates the development of more effective microneedle-based drug delivery and medical devices.