Testing of Soft Biological Materials

The present activity starts from a collaborations between the our group and IRCCS Policlinico San Matteo (Dr. Mazzola and Dr. Totaro). Such activity is a part of a multidisciplinary research whose primary aim is the histological and mechanical characterization of health and pathological aortic tissues. Such characterization is devoted to identify both circumferential and longitudinal variations of stiffness in the aorta district. Testing are executed according to a standard protocol which may be organized in the three following steps: (i) specimen preparation, (ii) mechanical testing and (iii) data post-processing.

1. Specimen preparation

Figure 1. Samples of ascending aorta. (b) Rectangular specimen with markers for extension measurements and adhesive sandpaper to ensure a define clamping in the grip and to prevent slippage during testing.

2. Mechanical testing.

Mechanical testing is performed into two consequent steps: (I) preconditioning to obtain repeatable stress-strain curves; and (ii) uni-axial tensile testing until specimen failure.

Figure 2. (a) Specimen P6-Sa1-Sp1a between grips at start of the test. (b) Rupture of specimen P6-Sa1-Sp1a. (c) Rupture of specimen P6-Sa1-Sp1c.

3. Data post-processing

Figure 3. Data post-processing of TestWorks4 software. (a) Hysteresis stress-strain curves of specimen P6-Sa1-Sp1a. (b) Uniaxial tensile stress-strain curves of specimen P6-Sa1-Sp1a.