A Novel Scalable Approach to Solid Metal Microneedle Fabrication via an Automated Modified Wire Bonding Process
Date
2024-01-15
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Abstract
Hypodermic needles have played a pivotal role in medical treatments; however, their use often incites fear due to pain and tissue trauma. Microneedle arrays present a promising alternative, with their smaller size resulting in reduced pain and trauma, however they have faced manufacturing scale-up challenges due to the complex microfabrication processes involved, precluding their widespread adoption into clinical practice. This research introduces a novel microneedle fabrication method utilizing a modified wire bonding process, enabling rapid iteration of designs on a single automated system. Key fabrication parameters, such as loop settings and wire bonding capillary shape, were explored to understand their impact on microneedle geometry. This study finds how specific wire bonding parameters can influence microneedle tip sharpness, crucial for efficient skin penetration. Additionally, the research delves into how these parameters affect microneedle length, a crucial factor for delivering drugs to a sufficient depth below skin. A significant aspect of this work involved investigating three different bonding wire diameters (25, 33, and 50 µm). The findings revealed that the largest diameter, 50 µm, exhibited optimal performance in terms of robustness, and had the least tendency to bend upon insertion into porcine skin tissue, and the lowest failure rate during microneedle fabrication. Initial tests on porcine skin validated the effective penetration ability of the wire bonded microneedles. A computational simulation was also developed to illustrate how the unique tip shapes, achievable through wire bonding, can enhance skin penetration. This iterative process, encompassing simulation, fabrication, and testing, underscores the potential of this novel fabrication method as a versatile platform technology. This research lays a solid foundation for broad applications, paving the way for future optimizations and adaptations tailored to specific microneedle requirements for different applications.
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Microneedles, Microneedle array, Wire bonding, Ball bonding, Additive fabrication process for microneedle arrays, Microfabrication, bioMEMS, Microarray patch, Solid metal microneedles, Metal microneedles
Citation
Haider, S. K. (2024). A novel scalable approach to solid metal microneedle fabrication via an automated modified wire bonding process (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.