The four-terminal piezotransducer: theory and comparison with piezoresistive bridge

The analogy between mechanical and electromagnetic transducers is presented in this paper. Some practically important analytical results are obtained. These results form the basis of the method developed for calculations of the sensitivity of four-terminal piezotransducers. The influence of geometrical dimensions of the transducer (such as length and width) has mainly been investigated. The optimal location and angular orientation of the current spread region on a rectangular elastic element is found for the (100) crystallographic plane with the aid of the variation method. A comparison with a Wheatstone bridge shows that the sensitivities of the bridge circuit and four-terminal piezotransducer are approximately equal.