A two-scale FEM-BAM approach for fingerpad friction under electroadhesion

TL;DR

This paper introduces a two-scale FEM-BAM modeling approach to simulate fingerpad friction under electroadhesion, capturing both macroscopic contact mechanics and microscopic roughness effects to better understand tactile perception.

Contribution

It presents a novel coupled FEM and BAM model that integrates multi-scale physical phenomena for electroadhesion-based tactile display analysis.

Findings

Model predicts electroadhesion effects consistent with experiments

Coupled approach captures microscopic and macroscopic contact behaviors

Framework can be extended to neural models for perception analysis

Abstract

The complex physics behind electroadhesion-based tactile displays poses an enormous modeling challenge since not only the fingerpad structure with multiple nonlinear layers, but also the roughness at the microscopic scale play a decisive role. To investigate tactile perception, a potential model should also offer the possibility to extract mechanical stimuli at the sites of the relevant mechanoreceptors. In this paper, we present a two-scale approach that involves a finite element model (FEM) at the macroscopic scale and a simple bearing area model (BAM) that accounts for the measured roughness on the papillary ridges. Both separate scales couple in an iterative way using the concept of an equivalent air gap. We show that the electroadhesion-induced changes in friction and contact area predicted by the proposed model are in qualitative agreement with recent experimental studies. In a simple example, we demonstrate that the model can readily be extended by a neural dynamics model to investigate the tactile perception of electroadhesion.