TABLE I.
Geometric and material properties of the constitutive layers for both the 0.5 MHz and the 1 MHz devices. The US wavelengths corresponding to 0.5 MHz and 1 MHz were calculated as 2.96 mm and 1.48 mm, respectively. The thicknesses refer to the layers shown in Fig. 1(b).
| Layer | Material | Thickness (μm) | Thickness/λ | Density (kg/m3) | Speed of sound (m/s) | |
|---|---|---|---|---|---|---|
| 1 MHz device | Transducer | PZT-4 | 1000 | 0.676 | 7600 | 4530 |
| Glue layer | Epoxy | 10 | 0.006 | 2156 | 2640 | |
| Matching layer | Macor® | 1200 | 0.811 | 5631 | 2520 | |
| Fluid layer | Water | 200 | 0.135 | 1000 | 1482 | |
| Reflector | Glass | 170 | 0.115 | 2200 | 5710 | |
| 0.5 MHz device | Transducer | PZT-4 | 2000 | 0.676 | 7600 | 4530 |
| Glue layer | Epoxy | 10 | 0.003 | 2156 | 2640 | |
| Matching layer | Macor® | 700 | 0.236 | 5631 | 2520 | |
| Fluid layer | Water | 370 | 0.125 | 1000 | 1482 | |
| Reflector | Glass | 170 | 0.057 | 2200 | 5710 |