Topographic De-adhesion in the Viscoelastic Limit

TL;DR

This paper extends the understanding of topographic de-adhesion mechanisms to viscoelastic biofoulants, revealing how time-dependent material properties influence surface self-cleaning strategies.

Contribution

It introduces a combined analytical and finite element model to analyze the non-linear, time-dependent interactions affecting de-adhesion in viscoelastic biofoulants, expanding beyond elastic theories.

Findings

Theoretical predictions align well with numerical simulations.

Key parameters include biofoulant softening, relaxation time, and strain thresholds.

Insights enable tuning surface features for improved self-cleaning in viscoelastic regimes.

Abstract

The superiority of many natural surfaces at resisting soft, sticky biofoulants has inspired the integration of dynamic topography with mechanical instability to promote self-cleaning artificial surfaces. The physics behind this novel mechanism is currently limited to elastic biofoulants where surface energy, bending stiffness, and topographical wavelength are key factors. However, the viscoelastic nature of many biofoulants causes a complex interplay between these factors with time-dependent characteristics such as material softening and loading rate. Here, we enrich the current elastic theory of topographic de-adhesion using analytical and finite element models to elucidate the non-linear, time-dependent interaction of three physical, dimensionless parameters: biofoulant's stiffness reduction, product of relaxation time and loading rate, and the critical strain for short-term elastic de-adhesion. Theoretical predictions, in good agreement with numerical simulations, provide insight into tuning these control parameters to optimize surface renewal via topographic de-adhesion in the viscoelastic regime.