Viscoelastic Patch De-adhesion from Wrinkling Surfaces as a Model of Realistic Thrombus Behavior

Adhesion of thrombus to wrinkled arterial lumen has attracted increasing attention as researchers are striving to resolve fouling issues in biological and artificial surfaces. While thrombus is viscoelastic, the majority of current research assumes only the limiting elastic behavior. This work therefore studies the delamination of a viscoelastic patch, as a model for realistic thrombus from a wrinkling surface. Specifically, a viscoelastic patch is attached to the surface of an elastic bilayer which undergoes wrinkling with increasing amplitude under increasing applied compression on the two ends. At a critical wrinkling amplitude, the patch starts to de-adhere from the wrinkled surface. Finite element and analytical models based on energy minimization are developed to undertake a parametric study with varying relaxation properties, adhesion energies, and loading rates to determine their correlations with critical delamination amplitudes. This allows the investigation of how viscoelastic characteristics such as relaxation time (related to thrombus age) and the loading rate (related to pulse rate) influence the de-adhesion process, providing insight into native arterial topographic renewal mechanisms and design strategies for topographic vascular grafts.