Mechanochemical Effects of Adsorbates at Nanoelectromechanical Switch Contacts

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Fan Yang
  • Jing Yang
  • Yubo Qi
  • Maarten P. De Boer
  • Robert W. Carpick
  • Andrew M. Rappe

Detail(s)

Original languageEnglish
Pages (from-to)39238−39247
Journal / PublicationACS Applied Materials and Interfaces
Volume11
Issue number42
Online published24 Sept 2019
Publication statusPublished - 23 Oct 2019

Abstract

Herein, classical molecular dynamics simulations are used to examine nanoscale adsorbate reactions during the cyclic opening and closing of nanoelectromechanical system (NEMS) switches. We focus upon how reactions change metal/metal conductive contact area, asperity morphology, and plastic deformation. We specifically consider Pt, which is often used as an electrode material for NEMS switches. The structural evolution of asperity contacts in gaseous environments with molecules which can potentially form tribopolymers is determined by various factors, for example, contact forces, partial pressure and molecular weight of gas, and the fundamental reaction rates of surface adsorption and adsorbate linkages. The modeled systems exhibit significant changes during the first few cycles, but as the number of contact cycles increases, the system finds a steady-state where the morphologies, Pt/Pt contact area, oligomer chain lengths, amount of Pt transfer between opposing surfaces, and deformation rate stabilize. The stress generated during asperity contact increases the rate of reactions among the adsorbates in the contact region. This makes the size of the adsorbate molecules increase and thus more exposed metal, which implies higher electrical conductance in the closed contact, but more plastic deformation, metal-metal transfer, and mechanical work expended in each contact cycle.

Research Area(s)

  • adsorbates, conductance, mechanochemistry, molecular dynamics, multi-cycle contact, NEMS switch

Citation Format(s)

Mechanochemical Effects of Adsorbates at Nanoelectromechanical Switch Contacts. / Yang, Fan; Yang, Jing; Qi, Yubo et al.
In: ACS Applied Materials and Interfaces, Vol. 11, No. 42, 23.10.2019, p. 39238−39247.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review