Improved design of clinical and industrial ultrasonic transducers requires an impedance matching layer with efficient coupling of acoustic energy between the piezoelectric ceramic and the propagating medium with controlled acoustic properties and ease of manufacturing. Traditional impedance matching layers comprise solid particles surrounded by a polymer matrix. This is prepared separately and then bonded to the piezoelectric layer. In this paper a new technique for making an integrated acoustic impedance matching layer is described. This is made by making a series of shallow grooves at the surface of the bulk piezoelectric ceramic layer. These grooves extend partially into the bulk piezoelectric ceramic. The depth of the grooves determines the thickness of the integrated impedance matching layer. By depositing an electrode that extends into the grooves the electrical potential distribution inside the integrated impedance matching layer is controlled. The integrated impedance matching layer is piezoelectrically inert. The principle of operation for the integrated impedance matching layer is described here. The impulse response for a transducer with the integrated impedance matching layer radiating into water is presented here. The experimental and the simulation results are compared showing a good correlation. [References: 3]
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