Design rules for a tunable merged-tip microneedle

Jungeun Lim; Dongha Tahk; James Yu; Dal-Hee Min; Noo Li Jeon

doi:10.1038/s41378-018-0028-z

Design rules for a tunable merged-tip microneedle

Microsyst Nanoeng. 2018 Oct 22:4:29. doi: 10.1038/s41378-018-0028-z. eCollection 2018.

Authors

Jungeun Lim^#^{1

2}, Dongha Tahk^#^{1

2

3}, James Yu⁴, Dal-Hee Min⁵, Noo Li Jeon^{1

2

3

4}

Affiliations

¹ 1School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 08826 South Korea.
² 2Division of WCU Multiscale Mechanical Design, Seoul National University, Seoul, 08826 South Korea.
³ 3Institute of Advanced Machinery and Design, Seoul National University, Seoul, 08826 South Korea.
⁴ 4Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, 08826 South Korea.
⁵ 5Department of Chemistry, Seoul National University, Seoul, South Korea.

^# Contributed equally.

Abstract

This publication proposes the use of an elasto-capillarity-driven self-assembly for fabricating a microscale merged-tip structure out of a variety of biocompatible UV-curable polymers for use as a microneedle platform. In addition, the novel merged-tip microstructure constitutes a new class of microneedles, which incorporates the convergence of biocompatible polymer micropillars, leading to the formation of a sharp tip and an open cavity capable of both liquid trapping and volume control. When combined with biocompatible photopolymer micropillar arrays fabricated with photolithography, elasto-capillarity-driven self-assembly provides a means for producing a complex microneedle-like structure without the use of micromolding or micromachining. This publication also explores and defines the design rules by which several fabrication aspects, such as micropillar dimensions, shapes, pattern array configurations, and materials, can be manipulated to produce a customizable microneedle array with controllable cavity volumes, fracture points, and merge profiles. In addition, the incorporation of a modular through-hole micropore membrane base was also investigated as a method for constitutive payload delivery and fluid-sampling functionalities. The flexibility and fabrication simplicity of the merged-tip microneedle platform holds promise in transdermal drug delivery applications.