Author ORCID Identifier
https://orcid.org/0000-0002-7830-0463
N/A
Document Type
Article
Publication Date
11-5-2021
College/Unit
Statler College of Engineering and Mining Resources
Department/Program/Center
Mechanical and Aerospace Engineering
Abstract
While the green production and application of 2D functional nanomaterials, such as graphene flakes, in films for stretchable and wearable technologies is a promising platform for advanced technologies, there are still challenges involved in the processing of the deposited material to improve properties such as electrical conductivity. In applications such as wearable biomedical and flexible energy devices, the widely used flexible and stretchable substrate materials are incompatible with high-temperature processing traditionally employed to improve the electrical properties, which necessitates alternative manufacturing approaches and new steps for enhancing the film functionality. We hypothesize that a mechanical stimulus, in the form of substrate straining, may provide such a low-energy approach for modifying deposited film properties through increased flake packing and reorientation. To this end, graphene flakes were exfoliated using an unexplored combination of ethanol and cellulose acetate butyrate for morphological and percolative electrical characterization prior to application on polydimethylsiloxane (PDMS) substrates as a flexible and stretchable electrically conductive platform. The deposited percolative free-standing films on PDMS were characterized via in situ resistance strain monitoring and surface morphology measurements over numerous strain cycles, with parameters extracted describing the dynamic modulation of the film’s electrical properties. A reduction in the film resistance and strain gauge factor was found to correlate with the surface roughness and densification of a sample’s (sub)surface and the applied strain. High surface roughness samples exhibited enhanced reduction in resistance as well as increased sensitivity to strain compared to samples with low surface roughness, corresponding to surface smoothing, which is related to the dynamic settling of graphene flakes on the substrate surface. This procedure of incorporating strain as a mechanical stimulus may find application as a manufacturing tool/step for the routine fabrication of stretchable and wearable devices, as a low energy and compatible approach, for enhancing the properties of such devices for either high sensitivity or low sensitivity of electrical resistance to substrate strain.
Digital Commons Citation
Loh, Harrison A.; Marchi, Claudio; Magagnin, Luca; and Sierros, Konstantinos A., "Graphene Flake Self-Assembly Enhancement via Stretchable Platforms and External Mechanical Stimuli" (2021). Faculty & Staff Scholarship. 3061.
https://researchrepository.wvu.edu/faculty_publications/3061
Source Citation
Loh, H. A., Marchi, C., Magagnin, L., & Sierros, K. A. (2021). Graphene Flake Self-Assembly Enhancement via Stretchable Platforms and External Mechanical Stimuli. ACS Omega, 6(45), 30607-30617. https://doi.org/10.1021/acsomega.1c04368
Comments
Copyright © 2021 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
This article received support from the WVU Libraries' Open Access Author Fund.