Fabrication of microcapillaries and waveguides for single molecule detection

M. E. Foquet, J. Han, A. Lopez, W. Wright, H. G. Craighead

Research output: Contribution to journalConference articlepeer-review

12 Scopus citations


We are investigating fabrication techniques that can be used to form arbitrarily shaped fluid capillaries at dimensions below l μm. We are also considering processes and materials for forming optical waveguides in the same devices with the same fabrication processes. The intent is to develop fabrication methods that can be used to make optical/fluid-flow systems for greater miniaturization, integration and parallelism of optical excitation and detection systems for the sampling of small volumes. We have demonstrated fabrication processes that enable the creation of functional fluid channels and waveguide in a single step. The independent operation of capillary channels and waveguides has been demonstrated and a system is designed for future testing of in-plane optical excitation of fluorescence. Capillaries with widths below 1 μm dimensions have been fabricated using photolithography and reactive ion etching in glass and silicon substrates. We have driven dye labeled DNA molecules electrophoretically through the micrometer size channels and observed individual molecules fluorescence. Surface energy on the high relative surface area channels is significant in the filling of the channels with aqueous solutions and treatment of the liquid contacting surfaces has influence on the system behavior. Light is coupled into the waveguide through gratings fabricated by electron-beam lithography.

Original languageEnglish (US)
Pages (from-to)141-147
Number of pages7
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1998
EventMicro - and Nanofabricated Structures and Devices for Biomedical Environmental Applications - San Jose, CA, United States
Duration: Jan 26 1998Jan 27 1998


  • Electrophoresis
  • Integrated optics
  • Single molecule detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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