Quartz Crystal Microbalance Sensor
The quartz crystal microbalance (QCM) sensor has recently been put into place in the Stanford CPIMA Shared Facilities and is experiencing a surge of use. This sensor is extraordinarily sensitive to mass changes associated with the deposition of material onto the surface of a quartz crystal. These changes are sensed as changes in the natural resonant frequency of the QCM.
The QCM is also sensitive to the mechanical losses in the film, which give rise to increasing resonance widths. This increasing width or decreasing quality factor (Q) is measured as an increase in the equivalent circuit resistance.