# A Layer-Based Model for Frictional Sliding of Pillar Arrays

## TL;DR

This paper introduces a new model to simulate and understand friction between interdigitated micropillar surfaces, inspired by biological systems.

## Contribution

A novel layer-based physical model is developed to predict friction and deformation mechanisms in micropillar arrays.

## Key findings

- The model accurately predicts shear friction force in sliding experiments.
- Deformation mechanisms vary with misorientation and height overlap of the pillars.
- Interpillar coupling significantly influences the overall frictional behavior.

## Abstract

Bioinspired
micropatterned
surfaces have been studied
as a way
to enhance or control interfacial mechanical properties. Here, we
study friction for the relative sliding of two interdigitated pillar
surfaces. The overall frictional force originates from individual
pillar–pillar interactions across the interface as well as
the interpillar coupling within each substrate. In this study, we
develop a layer-based physical model to simulate the contact and sliding
behavior of these pillar arrays. The system is modeled as comprising
four layers of nodes, with uniform shear displacement applied to the
top layer, while the bottom one is held fixed. Nodes in the inner
two layers represent the joints between the pillars and the substrate.
The model predicts shear friction force and reveals underlying deformation
mechanisms at various misorientations and height overlaps, in good
agreement with measured friction in sliding experiments.