Imaging device with ultrasound transducer array

A method of forming an acoustic window on an ultrasound transducer array for an ultrasound probe or catheter, the ultrasound transducer array comprising a plurality of ultrasound transducer elements that define an ultrasound emitting surface of the ultrasound transducer array, the method comprising:

• depositing a first solution that comprises a hydrocarbon elastomer and an antioxidant in an organic solvent on the ultrasound emitting surface;
• removing the organic solvent to form a first layer of the acoustic window contacting the ultrasound emitting surface, said first layer comprising the hydrocarbon elastomer and the antioxidant such that the hydrocarbon elastomer in the first layer is prevented from cross-linking, thereby providing the first layer with a first Shore A hardness;
• depositing a second solution comprising the same hydrocarbon elastomer in a further organic solvent on the first layer;
• removing the further organic solvent to form a second layer of the acoustic window contacting the first layer, wherein the second layer is an outer layer of the acoustic window, wherein the second layer does not include the antioxidant or the second layer includes a smaller amount of the antioxidant than in the first layer;
• and
• at least partially cross-linking the hydrocarbon elastomer in the second layer because the second layer does not include the antioxidant or the second layer includes a smaller amount of the antioxidant than in the first layer such that the second layer comprises a greater second Shore A hardness greater than the first layer the first Short A hardness,
• wherein the same hydrocarbon elastomer is adapted to provide:
• acoustic coupling with the ultrasound emitting surface based on the first Shore A hardness of the first layer;
• and
• at least one of mechanical protection or a moisture barrier for the ultrasound transducer array based on the second Shore A hardness of the second layer.