Preparation of Microneedle Array Mold Based on MEMS Lithography Technology.

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Microneedle arrays (MNAs) offer painless, minimally invasive transdermal drug delivery with precise dosage control.
• Existing fabrication methods have limitations in achieving desired MNA geometries and functionalities.

Purpose of the Study:

• To compare three novel microneedle array (MNA) fabrication methods using Microelectromechanical Systems (MEMS) technology.
• To evaluate the reproducibility, accuracy, and potential applications of MNAs produced via different manufacturing routes.

Main Methods:

• Fabrication of metal MNAs using the planar pattern-to-cross-section (PCT) method with LIGA (Lithography, Electroplating, Molding) technology.
• Production of PDMS quadrangular pyramid MNAs via silicon wet etching and SU-8 processing.
• Creation of PDMS conical MNAs using tilting rotary lithography on SU-8 photoresist.

Main Results:

• All three methods utilize parallel subtractive manufacturing with a reproducibility and accuracy range of 2-11%.
• LIGA-based MNAs are hollow with an aspect ratio up to 30, suitable for blood extraction and drug injection.
• Engraving and UV exposure processes yield MNAs of 600 μm and 150 μm height, respectively, for sustained release and subcutaneous stimulation.

Conclusions:

• The developed MEMS-based fabrication techniques provide versatile platforms for creating diverse microneedle array designs.
• These methods enable precise control over MNA dimensions, facilitating applications from diagnostics to systemic drug delivery.