Dynamics and response of polymer-coated surface acoustic wave devices. Effect of viscoelastic properties and film resonance

Journal Article · Fri Jul 15 04:00:00 EDT 1994 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00086a003· OSTI ID:6915791

Martin, S J; Frye, G C ^[1]; Senturia, S D ^[2]

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1. Sandia National Lab., Albuquerque, NM (United States)
2. Massachusetts Inst. of Technology, Cambridge, MA (United States)

The response of polymer-coated surface acoustic wave (SAW) devices to temperature changes and polymer vapor absorption is examined. A perturbational approach is used to relate velocity and attenuation responses to film translational and strain modes generated by the SAW. Two distinct regimes of film behavior arise, causing different SAW responses. For glassy films, displacement is nearly uniform across the film thickness, varying only in the direction of propagation. A model developed to predict velocity and attenuation in this regime (model 1), reduces to the familiar Tiersten (Wohltjen) equation for purely elastic films. For elastomeric (rubbery) films, inertial effects cause a phase lag to occur across the film for shear displacements. A model to account for these cross-film displacement gradients (model 2) predicts a characteristic resonant response when the film phase shift reaches n[pi]/2, where n is an odd integer. These model predictions are compared with measured responses from polyisobutylene-coated SAW devices as temperature is varied and during exposure to high vapor concentrations. 48 refs., 15 figs., 6 tabs.

• DOE Contract Number: AC04-94AL85000
• OSTI ID: 6915791
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Vol. 66:14; ISSN 0003-2700; ISSN ANCHAM
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
360606 -- Other Materials-- Physical Properties-- (1992-)
440800 -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
661300 -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ATTENUATION
COMPILED DATA
DATA
DEPOSITION
ELASTOMERS
FILMS
FLUIDS
GASES
INFORMATION
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYOLEFINS
SOUND WAVES
STRAINS
SURFACE COATING
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSDUCERS
VAPORS
WAVE PROPAGATION