An optimized hollow microneedle for minimally invasive blood extraction

Cheng Guo Li, Chang Yeol Lee, Kwang Lee, Hyungil Jung

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

The healthcare system relies widely on biochemical information obtained from blood sample extracted via hypodermic needles, despite the invasiveness and pain associated with this procedure. Therefore, an alternative micro-scale needle for minimally invasive blood sampling is highly desirable. Traditional fabrication techniques to create microneedles do not generate needles with the combined features of a sharp tip, long length, and hollow structure concurrently. Here, we report the fabrication of a microneedle long enough to reach blood vessels and sharp enough to minimize nerve contact for minimally invasive blood extraction. The microneedle structure was precisely controlled using a drawing lithography technique, and a sharp tip angle was introduced using a laser-cutting system. We investigated the characteristics of a microneedle with a length of 1,800 μm length, an inner diameter of 60 μm, a tip diameter of 120 μm, and a 15 bevel angle through in-vitro liquid extraction and mechanical strength analysis. We demonstrated that the proposed structure results in blood extraction at a reasonable rate, and that a microneedle with this geometry can reliably penetrate skin without breaking. We integrated this microneedle into a blood extraction device to extract a 20 μl volume of mouse blood in-vivo. Our optimized, hollow microneedle can potentially be incorporated with other cutting-edge technologies such as microactuators, biosensors, and microfluidic chips to create blood analysis systems for point-of-care diagnostics.

Original languageEnglish
Pages (from-to)17-25
Number of pages9
JournalBiomedical Microdevices
Volume15
Issue number1
DOIs
Publication statusPublished - 2013 Feb 1

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All Science Journal Classification (ASJC) codes

  • Biomedical Engineering
  • Molecular Biology

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