Effect of surface roughness on the response of thickness-shear mode resonators in liquids

Journal Article · Fri Oct 15 00:00:00 EDT 1993 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00068a033· OSTI ID:5069886

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

---

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

The effect of surface microstructure on the response of thickness-shear mode resonators in contact with liquids has been examined. Resonators were fabricated with different degrees of random surface roughness by polishing AT-cut quartz crystals with various abrasive particle sizes and then depositing conformal Cr/Au electrodes. The electrical response of liquid-contacted resonators was measured over a range of frequencies near resonance and fit to an equivalent-circuit model. A method is described for determining the complex shear mechanical impedance (the ratio of shear stress to particle velocity at the solid/liquid interface) from the equivalent-circuit elements. This impedance is sensitive to the influence of surface microstructure on the solid/liquid interaction. The surface mechanical impedance was measured while surface roughness, contacting liquid properties, device operating frequency, and liquid contact angle were varied. Results show that, for roughness features much less than the liquid decay length, the surface may be considered hydrodynamically smooth and the responses depend only on the density-viscosity product. As features become comparable to or larger than the decay length, new mechanisms, including liquid trapping and compressional wave generation, arise for energy storage and power dissipation. 53 refs., 14 figs., 3 tabs.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5069886
• Journal Information: Analytical Chemistry (Washington); (United States), Vol. 65:20; ISSN 0003-2700
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
LIQUIDS
DENSITY
SURFACE TENSION
VISCOSITY
QUARTZ
POLISHING
SURFACE PROPERTIES
RESONATORS
RESPONSE FUNCTIONS
SURFACES
MICROSTRUCTURE
ROUGHNESS
EXPERIMENTAL DATA
INTERFACES
MECHANICAL IMPEDANCE
MICROBALANCES
SHEAR
BALANCES
DATA
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUIDS
FUNCTIONS
IMPEDANCE
INFORMATION
MEASURING INSTRUMENTS
MINERALS
NUMERICAL DATA
OXIDE MINERALS
PHYSICAL PROPERTIES
SURFACE FINISHING
WEIGHT INDICATORS
400100* - Analytical & Separations Chemistry
661300 - Other Aspects of Physical Science- (1992-)