Bilayered tubes display internal undulations as arteries do under pressure

Endothelial tissues in arteries are widely known to undergo a wrinkling process when their internal pressure drops below a critical value. This mechanism occurs naturally in living systems due to stiffness mismatch in the tube layers when the driving pressure cycles between systolic and diastolic. Our work shows that a synthetic inner-lined elastic tube with a stiffness mismatch between the lining and the support displays similar behavior. We investigate the wrinkles' geometry, amplitude, and wavelength as a function of the pressure changes, comparing experimental results with a nonlinear physical model we developed recently.

We also experimentally studied the wrinkled patterns on single-layer membranes buckled under geometric constraints in a circular sector. The wavelength selection mechanism completely differs from the material mismatch of synthetic inner-lined tubes but remarkably reproduces the geometry of the observed wrinkling patterns.