Freeze casted microstructured PVA tissue phantoms using a microfabricated seed layer

Improved microstructured PVA phantoms mimicking fibrous tissue have been developed using a modified freeze casting process. In this work we find that by introducing an SU-8 layer containing microfabricated wells of dimensions 10-30 μm, which acts as an ice nucleation seed plate, greater control over the final sample structural properties can be achieved. SEM images reveal highly anisotropic microstructures with controllable pore dimensions between 1-40 μm depending on the seed layer used in the freeze casting process. Preliminary experimental characterization in the range 20-50 MHz reveals a significant dependence of the attenuation coefficient on sample dimension.