Separate density and viscosity measurements of unknown liquid using quartz crystal microbalance

Abstract

Aqueous liquids have a wide range of applications in many fields. Basic physical properties like the density and the viscosity have great impacts on the functionalities of a given ionic liquid. For the millions kinds of existing liquids, only a few have been systematically measured with the density and the viscosity using traditional methods. However, these methods are limited to measure the density and the viscosity of an ionic liquid simultaneously especially in processing micro sample volumes. To meet this challenge, we present a new theoretical model and a novel method to separate density and viscosity measurements with single quartz crystal microbalance (QCM) in this work. The agreement of experimental results and theocratical calculations shows that the QCM is capable to measure the density and the viscosity of ionic liquids.

Viscosity Measurement Sensor: A Prototype for a Novel Medical Diagnostic Method Based on Quartz Crystal Resonator

“…The results obtained show that, with the proposed method, there is an offset phenomenon concerning the measurements made with the rotational viscometer. On the other hand, [ 27 ] shows a different method for measure density and viscosity separately using volumes from 2 to 10 microliters (by drops); the results present a slight deviation concerning the theoretical values, the authors mention that the cleanliness of the crystal, the working state of the QCR circuit, and the temperature of the environment as the main sources of the error. In Reference [ 31 ], Johannsmann mentions that certain effects interfere with the measuring of viscosity originated for nanoscopic air bubbles, roughness, slip, and compressional waves.…”

“…The size (portability) and cost are the main advantages of the proposed prototype since, in experiments where QCRs are used to measure viscosity [ 25 , 26 , 27 ], large and expensive equipment, such as network analyzers or universal counters, are usually used.…”

“…The use of QCRs to measure battery lead-acid viscosity to determine the state of charge of the battery is shown in [ 26 ]. In Reference [ 27 ], a method is shown to determine density and viscosity separately by measuring droplets of various fluids. A previous study of viscosity measurements with Hyaluronic Acid (HA) was performed in our laboratory, and the results are shown in Reference [ 28 ].…”

Label-Free Protein Detection by Micro-Acoustic Biosensor Coupled with Electrical Field Sorting. Theoretical Study in Urine Models

“…A liquid defined at the QCM interface exposes an effective load for the resonator due to the finite in-liquid penetration depth of shear evanescent wave. Using the structured surface of the sensor, we not only get the opportunity to separately measure density and viscosity (as shown in [ 51 , 108 , 109 , 110 ]), but also allow the acoustic field to penetrate deeper into the liquid (to the height of structural elements), thereby increasing the sensor’s sensitivity to small changes in liquid density (which is possible with the certain choice of height, filling factor, and material of structural elements, as shown in 4.1). We propose to couple shear bulk acoustic resonator type of sensor with protein electric field manipulation, which causes modulation of the protein concentration over time in the near-surface region.…”

Method for QCM Resonator Device Equivalent Circuit Parameter Extraction and Electrode Quality Assessment

“…Biosensors are primarily used in a liquid environment, and QCM loading has an inhomogeneous structure [ 10 ]. Under these conditions, QCM has an effect not only on the mass [ 11 ] but also on the viscosity [ 12 ]. This phenomenon is manifested in the complexity behind the frequency shift interpretation when QCM is used in liquid applications [ 11 ].…”