Mass Loading in Coupled Resonators Consisting of SU-8 Micropillars Fabricated Over SAW Devices

Author

Ramakrishnan, N. ; Nemade, Harshal B. ; Palathinkal, Roy Paily

Author_Institution

Centre for Nanotechnol., Indian Inst. of Technol. Guwahati, Guwahati, India

Volume

11

Issue

2

fYear

2011

Firstpage

430

Lastpage

431

Abstract

Surface acoustic wave (SAW) sensors extensively employ mass loading effect of a sensing film coated over the surface of a SAW device. We report experimental and simulation results of mass loading by SU-8 micropillars (in place of sensing film) attached normal to the surface of SAW resonators. For certain size of micropillars, we have observed an increase in the resonance frequency of the resonator, in contrast to the decrease in the resonance frequency normally caused by mass loading. The SAW resonator and the pillars constitute a system of coupled resonators, and for high values of stiffness at the interface of the pillar and substrate the shift in the resonance frequency is positive.

Keywords

micromechanical resonators; microsensors; resonance; surface acoustic wave sensors; SAW device; SAW resonator; SU-8 micropillar; coupled resonator; mass loading; microsensor; resonance frequency; sensing film; surface acoustic wave sensor; Finite element methods; Loading; Optical resonators; Resonant frequency; Sensors; Surface acoustic waves; Microsensors; microelectromechanical devices; resonance; surface acoustic wave (SAW) devices;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2010.2074193

Filename

5585673