Solid Micro Horn Array (SMIHA) for Acoustic Matching

摘要

Transduction of electrical signals to mechanical signals and vice-versa in piezoelectric materials is controlled by thematerial coupling coefficient. In general in a loss-less material the ratio of energy conversion per cycle is proportional tothe square of the coupling coefficient. In practical transduction however the impedance mismatch between thepiezoelectric material and the electrical drive circuitry or the mechanical structure can have a significant impact on thepower transfer. In this paper a novel method of matching the acoustic impedance of structures to the piezoelectricmaterial are described and discussed in relation to the objective of increasing power transmission and efficiency. Intypical methods the density and acoustic velocity of the matching layer is adjusted to give "ideal" matching between thetransducer and the load. The approach discussed in this paper utilizes solid micro horn arrays in the matching layerwhich channel the stress and increase the strain in the layer. This approach is found to have potential applications inenergy harvesting, medical ultrasound and in liquid and gas coupled transducers.