Piezoelectric composite sensors

Piezoelectric composite sensors consist of an electrically active piezoelectric phase combined with an electrically inert second phase. Typically, this second phase is a polymer, although in some cases it is a metal. This chapter will discuss the rationale behind this approach to sensor design. It will begin with a brief review of piezoelectricity, followed by the important commercial piezoelectric sensor materials and their relevant properties, and subsequently the need for incorporating them into composite form. The chapter will conclude by discussing the principle two-phase composite sensor configurations and their properties, the main commercial manufacturing techniques, and some practical applications.