| dc.description.abstract | Microneedle (MN) technology has emerged as an advanced method for transdermal
drug delivery, which focuses on diverse fabrication techniques to develop MNs with
various shapes and geometries. This study explores the application of CNC technology to
create MN master molds with extremely sharp tips. We examined the effects of two key
machine parameters, feed rate, and ramp angle, on the tip sharpness of the MNs. Our results
show that increasing both the feed rate and ramp angle can significantly reduce machine
time. However, a higher feed rate also leads to larger tip diameters and notable tip defects.
Conversely, changes in the ramp angle at a constant feed rate have minimal impact on tip
size. We identified an optimal condition balancing cutting time and tip sharpness at a feed
rate of 100 mm/min and a ramp angle of 1.5°. Additionally, we assessed the CNC's
capability to produce needles with different tip angles (from 21° to 70°). The findings
confirm that needles with varying tip angles maintained tip diameters below 10 μm, with
needles having a 50° tip angle exhibiting the sharpest tips at approximately 3.3 μm. Further
compression, insertion, and diffusion tests were conducted to evaluate the performance of
needles with different geometries. | en_US |
