Advances in the Mass Sensitivity Distribution of Quartz Crystal Microbalances: A Review

Abstract

A quartz crystal microbalance (QCM) is a typical acoustic transducer that undergoes a frequency shift due to changes in the mass of its surface. Its high sensitivity, robustness, small size design, and digital output have led to its widespread development for application in the fields of chemistry, physics, biology, medicine, and surface science. Mass sensitivity is one of the vital parameters and forms the basis for quantitative analysis using QCMs. This review firstly introduces the importance, definition, calculation, and measuring method of the mass sensitivity and then focuses on reviewing the influence of electrode parameters (including electrode shape, electrode diameter, electrode thickness, electrode material, etc.) on the mass sensitivity distribution of QCMs. Finally, the effect of the operating frequency on the mass sensitivity of QCMs is also analyzed.

Adsorbate Induced Transformations of Ovalbumin Layers in Volatile Organic Solvents: QCM Study of a Potential Bio-Sniffer for Acute Toxicity Assays

“…Since ovalbumin is a globular protein incapable of forming multilayer coatings, it is only necessary to ensure the initial formation of a monolayer of native protein molecules on the surface. For metal surfaces of gold or silver, this can be achieved by simply increasing the concentration of albumin in solution (in the volume of a drop) to more than 1 mg/mL [9]. In this case, the competition between the process of protein adsorption in its native form and the process of protein unfolding induced by the surface [10] is strongly shifted towards adsorption.…”

Study of Force-Frequency Characteristics in AT-Cut Strip Quartz Crystal Resonators with Different Rotation Angles

“…The quartz crystal resonator (QCR) consists of a quartz substrate sandwiched between two electrodes. It is widely used as a sensor for measuring external parameters, such as pressure [ 1 , 2 ], mass [ 3 , 4 , 5 ], and humidity [ 6 , 7 , 8 ], due to its compact size, high frequency, stability, and good repeatability.…”

Scanning time-resolved measurement of transient lattice strain on quartz oscillators resonating under alternating electric field

“…[2][3][4][5] The mass sensitivities of QCM sensors strongly depend on the shapes of the crystal and the metal electrodes deposited on the crystal surface. [6][7][8][9][10][11] Disk-shaped flat AT-cut crystals with circular electrodes and their thickness shear vibration mode are commonly used for QCM sensors [Figs. 1(a) and 1(b)].…”

“…6,7,12,13) The maximum sensitivity decreases with increasing electrode diameter and decreasing elecrode thickness. [8][9][10][11] When small-area electrodes are deposited on a flat crystal surface, coupling with unwanted vibration modes causes energy loss and lowers the quality factor. 14) This coupling can be suppressed in convex-shaped crystals [Fig.…”