US 11,701,689 B2
Ultrasonic transducer
Nicholas Chris Chaggares, Markham (CA); Eric M. Rieder, Markham (CA); and Khachic Karshafian, Markham (CA)
Assigned to RESONANT ACOUSTICS INTERNATIONAL INC., Markham (CA)
Filed by Resonant Acoustics International Inc., Markham (CA)
Filed on Jul. 31, 2019, as Appl. No. 16/527,997.
Claims priority of provisional application 62/712,595, filed on Jul. 31, 2018.
Prior Publication US 2020/0038912 A1, Feb. 6, 2020
Int. Cl. B06B 1/06 (2006.01); H10N 30/85 (2023.01); G10K 11/02 (2006.01)
CPC B06B 1/067 (2013.01) [G10K 11/02 (2013.01); H10N 30/852 (2023.02)] 27 Claims
OG exemplary drawing
 
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.