P5J-1 Dual-Layer Transducer Array for 3-D Imaging

The difficulty in fabricating and connecting large numbers of 2-D array elements has limited the development of 2-D transducer array with more than 5000 elements. In this paper, we propose a dual-layer transducer array design which uses perpendicular 1-D arrays for 3-D imaging. This transducer design reduces the complexity of fabrication and the number of channels while maintaining adequate performance compared to a fully sampled 2-D transducer array. To demonstrate feasibility, we constructed a 4 cm times 4 cm prototype dual-layer transducer array which consists of 256 elements for each layer operating at 4 MHz. Both layers used P[VDF-TrFE] material. The -6 dB fractional bandwidth was 130% without matching layer. The measured crosstalk of P[VDF-TrFE] layer was -24 dB in the frequency range of 3 MHz-10 MHz. We also verified the performance of this transducer using a wire target phantom. The theoretical beamwidth was 0.62 mm compared to the measured beamwidth of 0.53 mm using coherence factor when f-number is 1.6.