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arXiv 1012.0766cond-mat.mes-hall
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层间剪切对石墨烯谐振器的影响

Effect of Interlayer Shear to Graphene Resonators

Yilun Liu, Zhiping Xu, Quanshui Zheng

摘要:

单层或几层石墨烯纳米带可以制成对环境变化具有极高灵敏度的弯曲谐振器。在这项工作中,我们研究了层间剪切对石墨烯纳米带的共振频率f的影响,通过分子动力学(MD)模拟和弹性模型分析,包括层间剪切。与经典薄梁理论预测的f~nl ^-2(l为梁长,n为层数)相反,分子动力学模拟结果显示了非常不同的依赖关系,f~l ^-1.36和f-fmono~(n-1)/n(fmono为单层梁的频率)。多层石墨烯条带的层间剪切模量远小于其层内杨氏模量,并且弱的层间相互作用不能维持相邻层中碳原子之间的配准。多层石墨烯纳米带在振动过程中会产生较大的剪切变形。因此,我们提出了一个多梁剪切模型(MBSM)考虑层间剪切能量的多层石墨烯纳米带。它使预测与直接MD模拟非常一致,无需任何拟合参数。这些结果对于多层石墨烯纳米带的各种应用具有重要意义,例如在纳米机电器件中,包括谐振器、传感器和致动器,其中层间剪切对变形、振动和能量耗散过程具有明显的影响。

英文摘要:

Graphene nanostrips with single or a few layers can be made into bending resonators with extremely high sensitivity to environment changes. In this work we study the effect of interlayer shear on resonant frequencies f of graphene nanostrips, via both molecular dynamics (MD) simulation and elastic model analysis incorporating interlayer shear. Contrary to the classical thin beam theory prediction f~nl^-2 (l is beam length and n layer number), MD simulation results reveal very different dependences, f~l^-1.36 and f - fmono~(n-1)/n (fmono is frequency of the monolayer beam). Interlayer shear modulus of multilayer graphene strips is much smaller than their intralayer Young's modulus, and the weak interlayer interaction can not maintain the registry between the carbon atoms in adjacent layers. Large shear deformation occurs during vibration of multilayer graphene nano-strips. Therefore we propose a multi-beam shear model (MBSM) with the interlayer shear energy of multilayer graphene nano-strips taken into account. It makes predictions consistent excellently with direct MD simulations without any fitting parameter required. The results are of importance for various applications of multi-layer graphene nano-strips, such as in nano-electromechanical devices including resonators, sensors and actuators, where interlayer shear has apparent impacts to deformation, vibration, and energy dissipation processes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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