Title: Computational micromechanics analysis of electron hopping and interfacial damage induced piezoresistive response in carbon nanotube-polymer nanocomposites

Xiang Ren, and Gary Don Seidel,
Dept. of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, 228 Randolph Hall (0203) Blacksburg, VA 24061, USA

A.K. Chaurasia,
Dept. of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Andrés I Oliva-Avilés,
División de Ingeniería y Ciencias Exactas, Universidad Anáhuac Mayab, Km 15.5 Carr. Mérida-Progreso, AP 96 Cordemex, 97310 Mérida, Yucatán, México

José J Ku-Herrera and Francis Avilés,
Centro de Investigación Científica de Yucatán, Unidad de Materiales, Calle 43, No. 130 Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, México

Smart Materials and Structures -- 2015 -- 24 065031

Abstract
In uniaxial tension and compression experiments, carbon nanotube (CNT)-polymer nanocomposites have demonstrated exceptional mechanical and coupled electrostatic properties in the form of piezoresistivity. In order to better understand the correlation of the piezoresistive response with the CNT dispersion at the mesoscale, a 3D computational multiscale micromechanics model based on finite element analysis is constructed to predict the effective macroscale piezoresistive response of CNT/polymer nanocomposites. The key factors that may contribute to the overall piezoresistive response, i.e. the nanoscale electrical tunneling effect, the inherent CNT piezoresistivity and the CNT mesoscale network effect are incorporated in the model based on a 3D multiscale mechanical–electrostatic coupled code. The results not only explain how different nanoscale mechanisms influence the overall macroscale piezoresistive response through the mesoscale CNT network, but also give reason and provide bounds for the wide range of gauge factors found in the literature offering insight regarding how control of the mesoscale CNT networks can be used to tailor nanocomposite piezoresistive response.

Key words: : piezoresistivity, CNT/polymer nanocomposites, multiscale, gauge factor