In-plane single-crystal-silicon microneedles for minimally invasive microfluid systems

Seung Joon Paik, Sangwon Byun, Jung Ming Lim, Yonghwa Park, Ahra Lee, Seok Chung, Junkeun Chang, Kukjin Chun, Dongil Cho

Research output: Contribution to journalConference articlepeer-review

110 Citations (Scopus)


This paper reports an in-plane single-crystal-silicon microneedle array, its mechanical safety, its integration with a polydimethylsiloxane (PDMS) microfluid chip, as well as in vitro and ex vivo test results. The fabricated microneedle arrays have buried microchannels, which are fabricated by using the processes of anisotropic dry etching, isotropic dry etching, and trench-refilling. The microchannel diameter is about 20μm. Several needle dimensions and shapes were investigated, and the microneedle shape was optimized using mechanical strength analysis. A 100μm wide, 100μm thick, and 2mm long microneedle shaft with the tip taper angle 30° and the isosceles triangle tip shape is strong enough to endure 0.248mNm of out-of-plane bending moment and 6.28N of in-plane buckling load. Then, the microneedle array is integrated with a PDMS microfluid chip. The microneedle integrated microfluid chip is tested in vitro, by injecting black ink into a methanol-filled petridish, and Rhodamine B dye into 1% agarose gel through microchannels of the integrated microneedle. The integrated microfluid chip is also tested ex vivo, by injecting Rhodamine B dye into a chicken breast flesh. In this ex vivo test, the penetration force was measured. For the optimized microneedle shaft, the penetration force was 80.9mN, and this force is less than 1.3% of the buckling force, which is 6.28N.

Original languageEnglish
Pages (from-to)276-284
Number of pages9
JournalSensors and Actuators, A: Physical
Issue number2-3
Publication statusPublished - 2004 Sept 1
Externally publishedYes
EventSelected Papers from Transducers 03 - Boston, MA, United States
Duration: 2003 Jun 82003 Jun 12

Bibliographical note

Funding Information:
This research, under the contract project code M101KA010006-03K0101-00610, has been supported by the Intelligent Microsystems Center ( ), which carries out one of the 21st century’s Frontier R&D Projects sponsored by the Korea Ministry of Science and Technology.

Copyright 2008 Elsevier B.V., All rights reserved.


  • Diagnosis systems
  • Microfluid chip
  • Microneedle
  • PDMS

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering


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