title: Effects of fine metal oxide particle dopant on the acoustic properties of silicone rubber lens for medical array probe.
abstract: The effects of fine metal oxide particles, particularly those of high-density elements (7.7 to 9.7 x 10(3) kg/m3), on the acoustic properties of silicone rubber have been investigated in order to develop an acoustic lens with a low acoustic attenuation. Silicone rubber doped with Yb2O3 powder having nanoparticle size of 16 nm showed a lower acoustic attenuation than silicone rubber doped with powders of CeO2, Bi2O3, Lu2O3 and HfO2. The silicone rubber doped with Yb2O3 powder showed a sound speed of 0.88 km/s, an acoustic impedance of 1.35 x 10(6) kg/m2s, an acoustic attenuation of 0.93 dB/mmMHz, and a Shore A hardness of 55 at 37 degrees C. Although typical silicone rubber doped with SiO2 (2.6 x 10(3) kg/m3) shows a sound speed of about 1.00 km/s, heavy metal oxide particles decreased the sound velocities to lower than 0.93 km/s. Therefore, an acoustic lens of silicone rubber doped with Yb2O3 powder provides increased sensitivity because it realizes a thinner acoustic lens than is conventionally used due to its low sound speed. Moreover, it has an advantage in that a focus point is not changed when the acoustic lens is pressed to a human body due to its reasonable hardness.
authors: Advanced Electron Devices Laboratory, Corporate Research and Development Center, Toshiba Corporation, Kawasaki, Japan. yasuharu.hosono@toshiba.co.jp
authors: Yasuharu
authors: Y
authors: Hosono
authors: Yohachi
authors: Y
authors: Yamashita
authors: Kazuhiro
authors: K
authors: Itsumi
mesh_terms: D000162:Acoustics; D000537:Aluminum Oxide / Q000737:chemistry; D001729:Bismuth / Q000737:chemistry; D002563:Cerium / Q000737:chemistry; D004867:Equipment Design; D006195:Hafnium / Q000737:chemistry; D008187:Lutetium / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D012828:Silicones / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014463:Ultrasonography / Q000295:instrumentation*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D010087:Oxides; D012828:Silicones; C009495:titanium dioxide; D002563:Cerium; D008187:Lutetium; C030583:ceric oxide; C033301:bismuth oxide; D014025:Titanium; D000537:Aluminum Oxide; D015018:Ytterbium; D001729:Bismuth; D006195:Hafnium