Geometric Parameter Optimization of 3D-Printed Microneedle Arrays Based on Comprehensive Mechanical Testing and...

Area of Science:

• Biomaterials Engineering
• Additive Manufacturing
• Microneedle Technology

Background:

• Microneedle arrays are promising for transdermal drug delivery.
• Optimizing their mechanical properties and manufacturability is crucial for clinical translation.
• Stereolithography offers high resolution for complex microneedle designs.

Purpose of the Study:

• To systematically characterize the mechanical performance and manufacturing reliability of stereolithography-printed microneedle arrays.
• To identify optimal geometric designs and array configurations for enhanced functionality.
• To provide quantitative data for the design of 3D-printed microneedle systems.

Main Methods:

• Fabrication of microneedle arrays with varying diameters (300-400 μm), aspect ratios (2:1, 3:1, 4:1), and array densities (1x1, 5x5, 10x10) using stereolithography.
• Mechanical compression testing up to 50 N to evaluate load-bearing capacity and displacement.
• Statistical analysis (Two-way ANOVA) to determine the influence of geometric design and array configuration on mechanical response.
• Manufacturing success rate assessment for different configurations.

Main Results:

• Geometry-dependent mechanical performance was observed, with low-aspect-ratio designs excelling in high-density arrays and high-aspect-ratio designs in single-needle formats.
• Manufacturing success rates significantly improved with increased array density, from 44.2% for single needles to 67.3% for 10x10 arrays.
• Design 5 (400 μm diameter, 3:1 aspect ratio) in a 10x10 configuration demonstrated optimal mechanical characteristics, including controlled displacement and a high safety factor (13.32).

Conclusions:

• Stereolithography enables the production of microneedle arrays with tunable mechanical properties and improved manufacturing yields.
• Optimal microneedle design is contingent on the intended application, balancing geometry and array configuration.
• The study provides critical quantitative guidelines for the rational design and optimization of 3D-printed microneedle arrays for transdermal applications.