Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 2009 | Supplemental Material + Accepted Version + Published
Journal Article Open

Using TIRF microscopy to quantify and confirm efficient mass transfer at the substrate surface of the chemistrode

Abstract

This paper describes experiments for characterizing mass transfer at the hydrophilic surface of the substrate in a chemistrode. The chemistrode uses microfluidic plugs to deliver pulses of chemicals to a substrate with high temporal resolution, which requires efficient mass transfer between the wetting layer and the hydrophilic surface of the substrate. Here, total internal reflection fluorescence microscopy (TIRFM) was used to image the hydrophilic surface of the substrate as plugs were made to flow over it. The surface of the substrate was rapidly saturated with a fluorescent dye as the fluroesecent plugs passed over the substrate, confirming effective mass transfer between the wetting layer and the surface of the substrate. The dynamics of saturation are consistent from cycle to cycle, indicating that the chemistrode can stimulate surfaces with high reproducibility. The number of plugs required to reach 90% saturation of the hydrophilic surface of the substrate, φ(90%), only weakly depended on experimental conditions (the Péclet number or the capillary number). Furthermore, over a wide range of operating conditions, φ(90%) was less than 4. These results are useful for improving the chemistrode and for understanding other phenomena that involve diffusional transfer in multiphase or recirculating flows near surfaces.

Additional Information

© IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Received 20 January 2009. Published 31 July 2009. his research was supported by the NIH Director's Pioneer Award 1DP1OD003584 and the NSF CRC CHE-0526693. RFI is a Cottrell Scholar of Research Corporation and a Camille Dreyfus Teacher-Scholar. A part of this work was performed at the MRSEC microfluidic facility funded by the NSF. We thank Elizabeth B Haney for contributions in English corrections and editing this manuscript.

Attached Files

Published - Ismagilov_NJP_TIRFM_in_chemistrode_Ms_DC.pdf

Accepted Version - nihms-136237.pdf

Supplemental Material - movie_S1.mov

Supplemental Material - movie_S2.mov

Files

nihms-136237.pdf
Files (5.0 MB)
Name Size Download all
md5:dbb6364340c1bd83799aefe0ab814024
344.8 kB Download
md5:a71e26b46ea3ea3e37016c068e6597ea
1.4 MB Preview Download
md5:e1da04efd5981c0f4e467d3acd1f9123
617.0 kB Preview Download
md5:4fdfbf1392b101406858982f4d69653e
2.7 MB Download

Additional details

Created:
August 21, 2023
Modified:
October 24, 2023