Graphene Mechanics

Graphene might be one of the most important materials in human history [1–4]. As a monatomic layer of carbon atoms in a honeycomb lattice, graphene possesses extraordinary mechanical properties, in addition to other amazing properties. The mechanical properties are of extreme importance for several potential applications, including tailoring other properties with strain engineering [5]. It is worth noting that the first fabrication of graphene is through mechanical exfoliation. As a fact, Mechanical exfoliation is still a popular approach for the scalable production of graphene [6]. In this Special Issue, we focus on the cutting-edge studies of graphene mechanics, from both theoretical and experimental investigations. In particular, this collection covers current areas of research that are concerned with the effect of the production method and/or the presence of defects upon the mechanical integrity of graphene, the work related to the effect of graphene deformation upon its electronic properties and the possibility of employing strained graphene in future electronic applications, and reviews of the experimental and theoretical results to date on mechanical loading of freely suspended or fully supported graphene. The Special Issue on “Graphene Mechanics" is intended to provide a unique international forum aimed at covering a broad description of results involving mechanical properties, mechanical loading and engineering, and applications. This special issue is very successful and contains 21 articles. Worldwide researchers working in a wide range of disciplines have contributed to this special issue. There are 21 papers in this special issue, with three review papers [7–9] and 18 original research papers [10–27], from experimental, computational, and theoretical investigations. Among them, there are seven experimental investigations. Here, we have a brief introduction of these 21 works in order of their publication date as follows. As the first paper on this special issue, Chi et al. reported the influence of epitaxial crystallization on the mechanical properties of polyamide 66/reduced graphene oxide nanocomposite injection bar using differencital scanning calorimeter and other various techniques [10]. Their tensile test results showed that the presence of fewer epitaxial crystals can improve the mechanical properties of a polymer. Using first-principles calculations, Yan et al. studied the strain effects on gallium nitride adsorption on defective and doped graphene [11]. Their calculations reveal that the vacancy defect core enhanced the adsorption stability of the adatom on graphene, whereas the incorporation of oxygen impurity greatly reduced the stable adsorption of the gallium and nitrogen adatoms. The lattice expansion led to increased stability for all adsorption sites and configuration surfaces, except for the nitrogen adatom adsorbed over the gallium atom in Ga-doped graphene. By local-probe techniques including three-dimensional force field spectroscopy, Ashino and Wiesendanger investigated the out-of-plane elasticities of convexly curved graphene [12]. The substantially small intrinsic modulus that complies with continuum mechanics has been found to increase significantly at atomically specific locations, where sp2 to sp3 re-hybridization would certainly take place.