3I-2. Low-Acoustic Attenuation and High-Mechanical Strength Silicone Rubber Lens Doped with ZnO Nano-Powder for Medical Array Probe

Effects of zinc oxide (ZnO) nanopowder dopant, on the acoustical and physical properties of silicone (Q) rubber have been investigated, in order to develop a low-acoustic attenuation, low sound velocity, and high-mechanical properties lens material for medical array probes. The ZnO-doped Q rubbers showed acoustic impedance (Z) = 1.29 to 1.46 ª 106 kgÌmEsE, acoustic attenuation = 0.54 to 0.74 dBÌmmEÌMHzE, and attenuation figure of merits (FOM) (attenuation ª sound velocity) = 471 to 621 at 37oC. The attenuation FOM values for the Q rubber lens material are the lowest attenuation ever reported. The performance of 7.5 MHz linear array probe using the ZnO-doped Q rubber lens showed an increase of 3.5 dB in sensitivity compared to that of conventional Q rubber lens doped with SiO2 powder. In addition, the material showed a high tear strength and a large elongation. The excellent mechanical properties of the ZnO-doped-Q rubber lens enable higher performance during longer operation in diagnosis compared with conventional Q rubber lens for medical array probe application.