The Technology of
Quartz Crystal Microbalance (QCM)

The Quartz Crystal Microbalance: an Entire Lab on the Sensor Surface 

openQCM is a scientific as much as a smart device based on the quartz crystal microbalance technology. A quartz crystal microbalance (QCM) is a surface sensitive technology capable of measuring phenomena at molecular scale. Thanks to its unique and flexible characteristics, the quartz crystal microbalance has a wide range of applications in the field of chemistry, biology and material sciences. It is like an entire laboratory on the surface of a crystal.

Sensing Principle 

The QCM sensor is based on the piezoelectric properties of the quartz crystal. The application of an alternating current causes the mechanical vibration of the quartz crystal in the MHz range. The QCM technique measures the variations in quartz frequency for measuring the mass variations on its surface. A quartz crystal is capable to sense mass variations down to 0.1 nanograms. It is a very flexible technology because it can be used in any experimental conditions such as air, vacuum and liquid environments. Frequency measurements are commonly made with high precision making QCM an highly­ sensitive analytical device.

• direct measurement; 
• real-time analysis; 
• high sensitivity; 
• high specificity;
• wide dynamic range;
• hyphenated methods;
• broad range of applications;
• label free measurement;
• cost effectiveness.

In most cases, only some of the above capabilities are available for the scientists in a single instrument to optimise their needs. Acoustic devices like QCM offer a unique opportunity, thanks to the fact that all of the above characteristics can be combined

  • Quartz Crystal Microbalance Technology

Applications

Quartz crystal microbalance technique has a wide area of practical applications. It is useful for monitoring the real­time variations of thin film deposition in any ambient conditions. Then QCM is very effective in measuring adsorption-­desorption of molecular layers, SAM self­assemblied monolayer, swelling rates, hydratation of thin film. It is also useful for sensing molecular structural changes caused by chemical reactions on its surface. QCM could be used as a tunable gas sensor and for monitoring the aerosol deposition in ambient conditions. The applications in liquid environment show enormous potentiality. QCM is very effective in measuring binding events on functionalized surface, such as antigen­-antibody binding and protein-­protein interactions. It is a powerful tool in life sciences, being able to sense DNA hybridization and specific drug compounds. These are just a few example of the possible applications of quartz crystal microbalance for your own research. The real question is: What you can do with an entire laboratory in the palm of your hand ?