Natural and synthetic piezoelectric materials for chemical sensors

The coupled crystal oscillator may have the resonant frequency disturbed by the addition of mass at the crystal surface, according to the Sauerbrey relationship. The shift in frequency of the system is proportional to the mass at the crystal surface. Divinylbenzene and pyrrole polymer materials are considered in conjunction with quartz crystals. Of equal interest are a family of piezoelectric polymers based on polyvinylidene fluoride (PVDF). The preparation and use of these synthetic materials is discussed alongside the naturally occurring materials, with particular reference to real-time chemical sensors. The piezoelectric material is made analyte specific by application of a surface coating doped with specific reaction sensitive molecules or ions