What does a quartz crystal microbalance measure?

Quartz Crystal Microbalance (QCM) is an extremely sensitive mass balance that measures nanogram to microgram level changes in mass per unit area. The heart of the technology is a quartz disc. The frequency of oscillation can be affected by the addition or removal of small amounts of mass onto the electrode surface.

How does quartz crystal microbalance work?

How does QCM work? QCM uses the ‘piezo-electric effect’ of a thin quartz crystal between two electrodes. When a mechanical strain is applied to a piezo-electric material, this results in the generation of an electrical potential across that material.

What is Sauerbrey equation?

The Sauerbrey equation is a useful empirical model in material science to represent the dynamics of frequency change denoted by Δ 𝑓 in an area, denoted by 𝐴 , of the electrode in terms of the increment of the mass, which is denoted by Δ 𝑚 , loaded on the surface of the crystal under a certain resonant frequency 𝑓 0 .

What is the mass of a quartz crystal?

60.083 g

Formula mass 60.083 g·mol−1
Color Colorless through various colors to black
Crystal habit 6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Twinning Common Dauphine law, Brazil law and Japan law

What is quartz crystal microbalance used for?

The quartz crystal microbalance (QCM) is a highly sensitive method for studying changes in the mass of thin films. A thin disk cut from a single crystal of piezoelectric quartz is the basic unit of the QCM, and on this are evaporated metal (usually gold) electrodes.

What is quartz sensor?

Piezoelectric quartz crystal sensor is a new product of sensing technology. Quartz crystal oscillation frequency is highly sensitive to the changes of crystal surface mass loading and reaction system physical properties such as density, viscosity, conductivity, and so on, with sub-ng levels of mass detection.

How does quartz crystal work as a sensor?

A quartz crystal microbalance (QCM) can detect tiny mass deposits on the sensor crystal by the resonance frequency change introduced by the addition of the small mass. Frequency measurements can be made with high precision; hence, it is easy to measure small mass increments with a QCM.

What is a TQCM?

A Temperature controlled Quartz Crystal Microbalance (TQCM) is a type of sensor which uses changes in the resonant frequency of a quartz crystal to determine the amount and rate at which mass is deposited onto the crystals surface.

What is the formula of quartz?

Silica (Quartz) is chemical compound silicon dioxide SiO2.

What is clear quartz good for?

Clear quartz This white crystal is considered a “master healer.” It’s said to amplify energy by absorbing, storing, releasing, and regulating it. It’s also said to aid concentration and memory. Physically, clear crystals are claimed to help stimulate the immune system and balance out your entire body.

What happens when quartz is compressed?

Quartz crystal has a very high quality factor. It has the characteristic that when mechanical stress (compression or stretching) is applied to its two faces (Figure 3.21), a potential difference V is generated across it. As soon as there is no voltage across it, the quartz crystal regains its initial shape.

How does quartz crystal microbalance ( QCM ) work?

Quartz Crystal Microbalance (QCM) is an extremely sensitive mass balance that measures nanogram to microgram level changes in mass per unit area. The heart of the technology is a quartz disc. Quartz is a piezoelectric material that can be made to oscillate at a defined frequency by applying an appropriate voltage usually via metal electrodes.

What is the Sauerbrey equation for quartz crystal?

Equation 1, typically referred to as the Sauerbrey equation, constitutes the basic principle of QCM technology. 2 For a 5 MHz AT-cut quartz crystal at room temperature, C is approximately equal to 17.7 ng/ (cm 2 ·Hz). This means that the addition of 17.7 ng/cm 2 of mass on a 5 MHz quartz crystal causes a frequency change of 1 Hz.

How is the frequency of quartz related to its mass?

Sauerbrey demonstrated, in 1959, that the frequency change (Δf) of oscillating quartz could be linearly related to its mass change (Δm) as expressed by where n is the overtone number and C is a constant that depends on the property of the crystal used.

What is the resonance frequency of a quartz disc?

When the corresponding alternating current is applied to the quartz disc, it will oscillate at its resonance frequency. The resonance frequencies are typically on the order of MHz and inversely proportional to the crystal thickness. The common 5 MHz quartz crystal has a corresponding thickness of approximately 330 µm.