Effect of microneedles shape on skin penetration and minimally invasive continuous glucose monitoring in vivo

Beelee Chua, Shashi P. Desai, Michael J. Tierney, Janet A. Tamada, Arvind N. Jina

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The effect of microneedle shape on skin penetration and minimally invasive continuous glucose monitoring (CGM) was successfully investigated. Straight silicon microneedle arrays (SSMA) and tapered silicon microneedle arrays (TSMA) were fabricated using standard silicon micromachining techniques. Microneedle heights were ∼325 μm and ∼350 μm and pitch was 400 μm and 450 μm, respectively. Mode-I planar crack and mode-II ring crack propagation were assumed for TSMA and SSMA penetration mechanisms, respectively. Skin penetration was first qualitatively evaluated via methylene blue staining. TSMA and SSMA were also mounted on CGM system prototypes and applied on human subjects with an impact velocity of 10 m/s and worn for 6.5 h. The hollow microneedles allowed the glucose from the interstitial fluid in the epidermis to diffuse into the sensor chamber of the CGM system prototype. Sensor currents from the applied CGM system prototypes ranged from 100 nA to 400 nA and they appeared to follow the trend of the reference blood glucose sensor that ranged from ∼90 to 220 mg/dL. The CGM system prototype with SSMA yielded lower sensor current than that with TSMA. This may be due to the SSMA preferential penetration of skin via mode-II ring crack propagation, resulting in possible lumen occlusion from displaced skin material.

Original languageEnglish
Pages (from-to)373-381
Number of pages9
JournalSensors and Actuators, A: Physical
Volume203
DOIs
Publication statusPublished - 2013 Oct 31

Keywords

  • Continuous glucose monitoring
  • Crack propagation
  • Interstitial fluid
  • Microneedle array
  • Microneedle shape
  • Skin penetration

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Effect of microneedles shape on skin penetration and minimally invasive continuous glucose monitoring in vivo'. Together they form a unique fingerprint.

  • Cite this