Measuring liquid properties with smooth- and textured-surface resonators.

摘要

The sensitivity of quartz resonators to surface mass accumulation enables their use in a number of sensing applications. The linear change in resonant frequency that occurs with mass accumulation allows the device to function as a general-purpose gravimetric detector or ''microbalance.'' The device is easily instrumented as a sensor by incorporating it as the frequency-control element of an oscillator circuit. The response of thickness shear mode (TSM) resonators in liquids is examined. Smooth-surface devices, which viscously entrain a layer of contacting liquid, respond to the product of liquid density and viscosity. Textured-surface devices, which also trap liquid in surface features, exhibit an additional response that depends on liquid density alone. Combining smooth and textured resonators in a monolithic sensor allows simultaneous measurement of liquid density and viscosity.