Acoustic lens for an ultrasound array

An ultrasound probe comprising:

• a capacitive micro-machined ultrasound transducer (CMUT) cell comprising:
• a substrate;
• a first electrode;
• a cell membrane comprising a second electrode, wherein the cell membrane opposes the first electrode and the substrate with a cavity therebetween, wherein the membrane is arranged to vibrate upon a cell activation;
• an acoustic lens overlaying the CMUT cell, wherein the acoustic lens comprises:
• a first layer comprising a thermoset elastomer selected from a hydrocarbon family such that the thermoset elastomer is formed of only hydrogen and carbon atoms, wherein the first layer has an inner surface arranged to face the array and an outer convex shaped surface arranged to oppose the inner surface;
• and
• a second layer coupled to the outer surface of the first layer and comprising thermoplastic polymer polymethylpentene and an elastomer selected from a polyolefin family (POE) blended therein,
• wherein the first layer has a first acoustic wave velocity and the second layer has a second acoustic wave velocity, said second wave velocity is larger than the first wave velocity, wherein the first layer is in direct contact with the cell membrane,
• wherein the thermoset elastomer comprises polybutadiene,
• wherein the first layer including polybutadiene further comprises particles embedded therein for acoustic impedance adjustment of the first layer, and
• wherein the particles in the first layer include ceramic particles and the selected elastomer comprises a copolymer having a first monomer being an alpha olefin and a second monomer being ethylene.