Polymer materials for pressure measurement

Polyvinylidene fluoride (PVDF) has been exploited for a number of transducing requirements: acoustic, ultrasonic and pressure related. Materials such as this have numerous advantages over conventional approaches. For example, they are very flexible and can be formed into complex geometries; transducers of very large surface area can be developed; they are relatively easy to deal with in terms of electroding and transducer construction and lend themselves very well to laboratory experiments. Whilst PVDF certainly has all these attributes, its sensitivity has always been of concern, especially in its role as an ultrasonic transducer. The authors consider the use of copolymers of vinylidene fluoride (VDF) and trifluoroethylene (TrFE) which offer a sensitivity increase of some six-fold over PVDF. They discuss the properties of these materials and some of the problems associated with the construction of transducing devices from them. These arise predominantly from the difficulty of finding good adhesives for such copolymers