Scalable fabrication of microneedle arrays via spatially controlled UV exposure

Hidetoshi Takahashi, Yun Jung Heo, Nobuchika Arakawa, Tesuo Kan, Kiyoshi Matsumoto, Ryuji Kawano, Isao Shimoyama

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


This paper describes a theoretical estimation of the geometry of negative epoxy-resist microneedles prepared via inclined/rotated ultraviolet (UV) lithography based on spatially controlled UV exposure doses. In comparison with other methods based on UV lithography, the present method can create microneedle structures with high scalability. When negative photoresist is exposed to inclined/rotated UV through circular mask patterns, a three-dimensional, needle-shaped distribution of the exposure dose forms in the irradiated region. Controlling the inclination angles and the exposure dose modifies the photo-polymerized portion of the photoresist, thus allowing the variation of the heights and contours of microneedles formed by using the same mask patterns. In an experimental study, the dimensions of the fabricated needles agreed well with the theoretical predictions for varying inclination angles and exposure doses. These results demonstrate that our theoretical approach can provide a simple route for fabricating microneedles with on-demand geometry. The fabricated microneedles can be used as solid microneedles or as a mold master for dissolving microneedles, thus simplifying the microneedle fabrication process. We envision that this method can improve fabrication accuracy and reduce fabrication cost and time, thereby facilitating the practical applications of microneedle-based drug delivery technology.

Original languageEnglish
Article number16049
JournalMicrosystems and Nanoengineering
Publication statusPublished - 2016
Externally publishedYes


  • Inclined/rotated lithography
  • Microneedle array
  • UV exposure ratio

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science (miscellaneous)
  • Condensed Matter Physics
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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