New piezoceramic composites make better transducers

11 February 2011

Morgan Technical Ceramics has introduced a range of piezoceramic composite materials that significantly improve the performance of ultrasound and sonar transducers used in medical, biometric, military and industrial applications.
Transducers made from the material provide better image resolutions enabling significant advances to be made in 4D ultrasound technology. Morgan also designs and manufactures complete transducers, and will work closely with OEMs to develop high performance systems.

The new piezoceramic is used to make 1-3 transducer and 2-2 transducer plates which provide high performance over the frequency range 200kHz to 4MHz. Finely pitched composite configurations offer lower acoustic impedance than traditional monolithic components, which helps improve imaging resolution.

The piezoceramic material is arranged in pillars with a polymer matrix filler. By combining the materials in this way, the overall density of the composite structure better matches the medium of the material through which sound travels. The lower acoustic impedance allows a higher energy transfer through body tissue or water, resulting in a lower reverberation level on the front face of the acoustic device.

Piezocomposite materials benefit from a damping effect of the polymer which reduces lateral vibration modes, cross coupling and spurious activity, resulting in improved transducer bandwidth. The piezoceramic composite eliminates the interference that a conventional monolithic material would exhibit, thus improving transmission efficiency and reception sensitivity.

Morgan Technical Ceramics’ transducer design engineer Ewan Campbell says there’s growing demand for increased imaging resolution. “We work closely with customers to develop components that meet their needs. Our design engineers can adjust the architecture, manufacturing process, material properties and proportional content of ceramic versus polymer to optimise performance for each application.”

The company offers piezoceramic custom composites in 1-3 and 2-2 architectures, in sizes up to 40mm square and in many shapes, including cylindrical, spherical and curved. In addition, it is able to offer complete transducers based on piezoceramic composite technology. Morgan Technical Ceramics has in-house underwater acoustic test tanks and pressure testing facilities which are used to validate the performance of different designs. This integration of all process steps enables the company’s specialists to develop custom solutions with short lead times.

Transducers can be designed with appropriate matching layers, encapsulation and cables, suitable for the harsh conditions found in marine environments, and manufactured in volume for many medical and industrial applications.