Four-Sided Tip-Separable Micro-Needle Device With Large Barb Formed By Anisotropic Wet Etching For Trans-Dermal Drug Delivery System

A novel type four-sided tip-separable microneedle device with a large barb was proposed for separating a needle tip easily during the skin insertion in the trans-dermal drug delivery systems. The proposed microneedle device was composed of a sharp needle tip and a base one, and the former was placed on the latter with the 45° off rotation angle in the needle axis for increasing the barb area in the tip needle. A symmetry property of a single crystallographic Si(100) substrate was applied to produce two Si master needles producing both tip and base needle structures respectively, and they were fabricated by anisotropic wet etching. Finally, a polymer based four-sided tip-separable microneedle device with the large barb was successfully produced by applying a mold process to the fabricated two Si master needles.