Figure 1.

The principle of simple-shear rheometry. A linear, simple-shear deformation is applied to a tissue or material specimen by the upper plate with a small-amplitude translational sinusoidal displacement x. A harmonic shear force F due to the viscoelastic response of the specimen is transmitted to the lower plate, separated from the upper plate by a gap size d. The contact area A between the specimen and the upper plate can be visualized from directly above through the transparent upper plate.