Liquid-Phase Chemical Sensing Using Lateral Mode Resonant Cantilevers

Authors

Luke A. Beardslee, Georgia Institute of Technology - Main CampusFollow
Kemal S. Demirci, Georgia Institute of Technology - Main Campus
Y. Luzinova, Georgia Institute of Technology - Main Campus
B. Mizaikoff, University of Ulm
Stephen M. Heinrich, Marquette UniversityFollow
Fabien Josse, Marquette UniversityFollow
Oliver Brand, Georgia Institute of Technology - Main CampusFollow

Document Type

Article

Language

eng

Format of Original

8 p.

Publication Date

9-2010

Publisher

American Chemical Society

Source Publication

Analytical Chemistry

Source ISSN

0003-2700

Original Item ID

doi: 10.1021/ac1010102

Abstract

Liquid-phase operation of resonant cantilevers vibrating in an out-of-plane flexural mode has to date been limited by the considerable fluid damping and the resulting low quality factors (Q factors). To reduce fluid damping in liquids and to improve the detection limit for liquid-phase sensing applications, resonant cantilever transducers vibrating in their in-plane rather than their out-of-plane flexural resonant mode have been fabricated and shown to have Q factors up to 67 in water (up to 4300 in air). In the present work, resonant cantilevers, thermally excited in an in-plane flexural mode, are investigated and applied as sensors for volatile organic compounds in water. The cantilevers are fabricated using a complementary metal oxide semiconductor (CMOS) compatible fabrication process based on bulk micromachining. The devices were coated with chemically sensitive polymers allowing for analyte sorption into the polymer. Poly(isobutylene) (PIB) and poly(ethylene-co-propylene) (EPCO) were investigated as sensitive layers with seven different analytes screened with PIB and 12 analytes tested with EPCO. Analyte concentrations in the range of 1−100 ppm have been measured in the present experiments, and detection limits in the parts per billion concentration range have been estimated for the polymer-coated cantilevers exposed to volatile organics in water. These results demonstrate significantly improved sensing properties in liquids and indicate the potential of cantilever-type mass-sensitive chemical sensors operating in their in-plane rather than out-of-plane flexural modes.

Comments

Accepted version. Analytical Chemistry, Vol. 82, No. 18 (September 2010): 7542-7549. DOI. © 2010 American Chemical Society. Used with permission.

Recommended Citation

Beardslee, Luke A.; Demirci, Kemal S.; Luzinova, Y.; Mizaikoff, B.; Heinrich, Stephen M.; Josse, Fabien; and Brand, Oliver, "Liquid-Phase Chemical Sensing Using Lateral Mode Resonant Cantilevers" (2010). Civil and Environmental Engineering Faculty Research and Publications. 69.
https://epublications.marquette.edu/civengin_fac/69