Predicting Human Touch Sensitivity to Single Atom Substitutions in Surface Monolayers

TL;DR

This study links molecular structure of surface monolayers to human tactile sensitivity, demonstrating that single atom substitutions can be detected through friction analysis, revealing new insights into chemical influences on touch perception.

Contribution

It introduces a method to predict and demonstrate human sensitivity to single atom differences in surface monolayers, connecting molecular chemistry with tactile perception.

Findings

Humans can distinguish between isosteric silanes with a single nitrogen-for-carbon substitution.

Differences in monolayer ordering affect tactile sensitivity.

The approach can be applied to other material systems for novel tactile interfaces.

Abstract

The mechanical stimuli generated as a finger interrogates the physical and chemical features of an object forms the basis of fine touch. Current approaches to study or control touch primarily focuses on physical features, but the chemical aspects of fine touch may be harnessed to create richer tactile interfaces and reveal fundamental aspects of tactile perception. To connect tactile perception with molecular structure, we systematically varied silane-derived monolayers deposited onto imperceptibly smooth surfaces and made predictions of human tactile sensitivity via friction and cross-correlation analysis. We predicted, and demonstrated, that humans can distinguish between two isosteric silanes which differ only by a single nitrogen-for-carbon substitution. The mechanism of tactile contrast originates from a difference in monolayer ordering which was replicated in two alkylsilanes with a three-carbon difference in length. This approach may be generalizable to other materials systems and lead to new tactile sensations derived from materials chemistry.