Title :
Properties of PVA tissue phantoms produced by directional solidification.
Author :
Gouws, Gideon ; Kivell, Dayna-Marie ; Ryan, Brett ; Thomson, Matt ; Dawson, Andrew
Author_Institution :
Sch. of Eng. & Comput. Sci., Victoria Univ. of Wellington, Wellington, New Zealand
Abstract :
Polyvinyl alcohol (PVA) cryogel samples prepared by repeated directional freezing and thawing steps are shown to display an anisotropic structure due to the effect of ice templating during the freezing process. The mechanical stability of the material is improved by the application of a number of directional freeze steps followed by thawing. The anisotropy of the material is confirmed by measurements of acoustic impedance and a simple model is proposed to explain the variation of impedance with the microstructure.
Keywords :
acoustic impedance; biological tissues; crystal microstructure; directional solidification; freezing; mechanical stability; melting; phantoms; polymers; PVA tissue phantom properties; acoustic impedance variation; anisotropic structure; directional solidification; ice templating effect; material anisotropy; mechanical stability; microstructures; polyvinyl alcohol cryogel; repeated directional freezing process; thawing steps; Acoustics; Crystals; Fingers; Ice; Impedance; Temperature measurement;
Conference_Titel :
Ultrasonics Symposium (IUS), 2011 IEEE International
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4577-1253-1
DOI :
10.1109/ULTSYM.2011.0331
