Dynamic stiffness of the contact between a carbon nanotube and a flat substrate in a peeling geometry

TL;DR

This study investigates the nanoscale contact mechanics and adhesion of a carbon nanotube on a flat substrate through dynamic stiffness measurements across a broad frequency range, revealing weak frequency dependence indicative of amorphous relaxation effects.

Contribution

It provides the first detailed measurement of the frequency-dependent dynamic stiffness of a nanotube-substrate contact in a peeling geometry, highlighting nanoscale relaxation phenomena.

Findings

Dynamic stiffness increases by a factor of 2 from DC to 20 kHz.

Weak frequency dependence suggests amorphous relaxation processes.

Nanoscale contact mechanics are influenced by relaxation effects.

Abstract

We study the physics of adhesion and the contact mechanics at the nanoscale with a peeling experiment of a carbon nanotube on a flat substrate. Using an interferometric atomic force microscope and an extended force modulation protocol, we investigate the frequency response of the stiffness of the nano-contact from DC to 20 kHz. We show that this dynamic stiffness is only weakly frequency dependent, increasing by a factor 2 when the frequency grows by 3 orders of magnitude. Such behavior may be the signature of amorphous relaxations during the mechanical solicitation at the nano-scale.