CPC B06B 1/067 (2013.01) [G10K 11/02 (2013.01); H10N 30/852 (2023.02)] | 27 Claims |
1. An ultrasonic transducer, comprising:
a piezoelectric composite layer configured to be in acoustic communication with a sample and having at least partially decoupled acoustic impedance and electrical impedance properties, the piezoelectric composite layer comprising:
an array of spaced-apart piezoelectric regions, each spaced-apart piezoelectric region being made from a piezoelectric material having a first acoustic impedance and a first electrical relative permittivity;
a filler material positioned between adjacent spaced-apart piezoelectric regions, the filler material comprising a polymer matrix having a second acoustic impedance and a second electrical relative permittivity, the second acoustic impedance being smaller than the first acoustic impedance, and the second electrical relative permittivity being smaller than the first electrical relative permittivity; and
a non-piezoelectric material in contact with the polymer matrix, the non-piezoelectric material having a third acoustic impedance and a third electrical relative permittivity, the third acoustic impedance being greater than the second acoustic impedance, and the third electrical relative permittivity being smaller than the first electrical relative permittivity;
an electrically insulating non-piezoelectric composite layer extending over the piezoelectric composite layer for electrically insulating the piezoelectric composite layer from the sample, the electrically insulating non-piezoelectric composite layer being acoustically matched to the piezoelectric composite layer and the sample, wherein the electrically insulating non-piezoelectric composite layer comprises high acoustic impedance electrically insulating material regions in contact with a second polymer matrix, the second polymer matrix being filled with a high density electrically insulating powder; and
one or more electrodes in electrical communication with the piezoelectric composite layer.
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