Ultrasound-assisted permeability improvement and acoustic characterization for solid-state fabricated PLA foams

In the present study, power ultrasound is applied to improve the permeability of the solid-state fabricated PLA foams with different cell sizes. It is experimentally proved that cell interconnection and the permeability is improved with the increasing of power ultrasound radiation intensity. Furthermore, an insert-substitution testing approach is put forward to perform acoustic measurement and property characterization for the PLA foams before and after ultrasound radiation. The experimental results indicate that the attenuation coefficient of the close-celled PLA foams decreases exponentially with respect to the saturation pressure and it shows linear behavior with respect to the ultrasound radiation intensity. The favorable results suggest the feasibility of the proposed technologies of ultrasound-assisted permeability improvement and acoustic characterization for the application of the solid-state foamed PLA foams in tissue engineering.