Institute of Functional Interfaces

Quarz Crystal Microbalance with Dissipation Monitoring (QCM-D)


Quartz crystal micro-balance with dissipation monitoring (QCM-D) is used to investigate molecular interactions and adsorption on different surfaces. The main applications are the determination the adsorption properties of biomaterials and functional surfaces, for proteins, lipids, polymers, metal-organic frameworks (MOFs), cells and bacteria.

 

 

QCM-D Anwendung

 

 

Measuring principle


A spontaneous excitation of the sensor with an AC voltage is used to oscillate the quartz disc with a frequency that is dependent on the total oscillating mass. The deposition of a thin film increases the oscillation and the resonant frequency decreases. This dependence is described by the Sauerbrey equation:

 

Sauerbrey

 


The Sauerbrey equation applies only for rigid films, because non-elastic films follow the exact oscillation, the oscillation is damped. For the quartz crystal micro-balance with dissipation monitoring (QCM-D) technology, after excitation the quartz crystal can swing freely and can be used to determine the damping properties of the mass and visco-elastic properties of the bonded film. The measurement is performed in real time.

 

 

QCM-D Geraet

Q-Sense's Quartz crystal micro-balance  E4