Building embedded microchannels using a single layered SU-8, and determining Young's modulus using a laser acoustic technique

Hui Yu*, Oluwaseyi Balogun, Biao Li, Todd W. Murray, Xin Zhang

*Corresponding author for this work

Research output: Contribution to journalArticle

50 Scopus citations


In this paper, an innovative method to create embedded microchannels is presented. The presented technology is based on a direct-write technique using a scanning laser system to pattern a single layered SU-8. The enormous flexibility of the scanning laser system can be seen in two key features: the laser pulsing can be controlled spot-by-spot with variable exposure doses, and the laser intensity penetrating into samples can be adjusted by varying the laser focus level. The UV laser direct-write method greatly simplifies the fabrication processes. Moreover, it can be set up in a conventional manufacturing environment without the need for clean room facilities. The second part of this paper describes the underlying theory and method to determine Young's modulus of exposed SU-8 by using a laser acoustic microscopy system. The laser-based ultrasonic technique offers a non-contact, non-destructive means of evaluation and material characterization. This paper will determine Young's modulus of UV exposed SU-8 generated with different exposure doses. Measurements show that Young's modulus is highly dependent on exposure dose. Young's modulus ranges from 3.8 to 5.4 GPa when the thickness of a fully cross-linked SU-8 microbeam varies from 100 to 205 μm with a gradually increased UV exposure dose.

Original languageEnglish (US)
Pages (from-to)1576-1584
Number of pages9
JournalJournal of Micromechanics and Microengineering
Issue number11
StatePublished - Nov 1 2004


ASJC Scopus subject areas

  • Instrumentation
  • Materials Science(all)
  • Mechanics of Materials
  • Computational Mechanics

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