Characterisation of anisotropic poly(vinyl-alcohol) gels prepared using a two-zone controlled directional freezing process

PVA phantoms prepared using an improved two-zone controlled directional freezing process exhibit tailorable, repeatable, anisotropic properties representative of real tissues. The directional freeze process induces a preferred microstructural orientation with significantly increased Young's Modulus along the direction of freezing. The uniformity of the microstructure is consistent throughout the sample as confirmed through velocity measurements.