Letters 2004 2, 69-72.
A Micromachined Fluidic
Structure for Capillary-based Sample Introduction into a Microbead Array
Y. Sohn, A. Goody,
E. V. Anslyn, J. T. McDevitt, J. B. Shear, D. P. Neikirk
The development of a micromachined fluidic structure for the introduction
of liquid samples into a chipbased
sensor composed of an array of polymeric microbeads is presented. The
consists of micromachined storage cavities combined with a covering glass
layer that confines the microbeads
and fluidic channels. In our sensor array, transduction occurs via optical
changes to receptors
or/and indicator molecules that are attached to the polymeric microbeads.
Hence, the confining structures
must also allow optical access to the microbeads. The fabrication process
has been selected to protect receptors
or/and indicator molecules that may be sensitive to the normal processes
used in chip fabrication.
One of the key parts of the structure is a passive fluid introduction
system driven only by capillary force.
This simple means of fluid introduction realizes a compact device. The
capillary flow on the inlet channel
has been studied, and the responses of the microbeads to the liquid sample
have been characterized. The
test results show that this system may be useful in a micro-total-analysis-system
(m-TAS) and biomedical