Measurement of mechanical properties of alginate beads using ultrasound

Alginate beads are one of the most common vehicles for encapsulation. When designing bioartificial organs, they are used as matrix for cell culture. Cell survival and activity depend essentially on the bead physical and mechanical properties. Our objective is to study the feasibility of evaluating mechanical properties of millimetric beads using an ultrasound technique. We show that Lamé’s first coefficient can be quantified and that the alginate gel is quasi-incompressible. The study also shows that the density and elastic coefficient vary with the bead concentration in alginate and that a quasilinear relation exists between the two properties. Mots clefs : alginate beads, mechanical properties, Lamé’s first coefficient, acoustic impedance, ultrasound