AC frequency characteristics of coplanar impedance sensors as design parameters

Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes, as coplanar impedance sensors, were integrated on them. Longitudinal design parameters, such as interelectrode spacing and electrode width, of coplanar impedance sensors were changed to determine AC frequency characteristics as design parameters. Through developing total impedance equations and modeling equivalent circuits, the dominant components in each frequency region were illustrated for coplanar impedance sensors and the measured results were compared with fitted values. As the ionic concentration increased, the value of the frequency-independent region decreased and cut-off frequencies increased. As the interelectrode spacing increased, cut-off frequencies decreased and total impedance increased. However, the width of each frequency-independent region was similar. As the electrode area increased, f(low) decreased but f(high) was fixed. We think that the decrease in R(Sol) dominated over the influence of other components, which resulted in heightening f(low) and f(hig)h. The interelectrode spacing is a more significant parameter than the electrode area in the frequency characteristics of coplanar sensors. The deviation of experimentally obtained results from theoretically predicted values may result from the fringing effect of coplanar electrode structure and parasitic capacitance due to dielectric substrates. We suggest the guidelines of dominant components for sensing as design parameters.
Publisher
ROYAL SOC CHEMISTRY
Issue Date
2005
Language
ENG
Keywords

CONTACTLESS CONDUCTIVITY DETECTION; DOUBLE-LAYER CAPACITANCE; ROUGH METAL-SURFACE; CAPILLARY-ELECTROPHORESIS; ANALYSIS SYSTEMS; ELECTRODES; DEVICES; OPTIMIZATION; GLASS; SEPARATIONS

Citation

LAB ON A CHIP, v.5, no.3, pp.270 - 279

ISSN
1473-0197
DOI
10.1039/b410325d
URI
http://hdl.handle.net/10203/3869
Appears in Collection
MS-Journal Papers(저널논문)
Files in This Item
000227186500005.pdf(834.49 kB)Download
  • Hit : 699
  • Download : 589
  • Cited 0 times in thomson ci
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡClick to seewebofscience_button
⊙ Cited 36 items in WoSClick to see citing articles inrecords_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0