Freestanding 2D materials are essentially under the adhesive boundary condition instead of the typically assumed clamped boundary condition, and the membrane deformation in pressure bulge testing is actually similar as that of the slack membrane. A new bulge testing model of freestanding 2D materials is proposed from the central strain of the bulged membrane under a given pressure, based upon which the elastic moduli of 2D materials can be properly characterized by an easy testing approach. In this approach, instead of using a complex pressure loading and measuring system, the 2D materials mounted on the substrate with circular holes are simply placed into the vacuum chamber, and the moduli of materials can be characterized from their central strain measured via Raman spectroscopy. In addition, finite element modeling (FEM) is employed to validate the effectiveness of the model proposed in the present work. The present approach can provide a useful guideline on effectively characterizing the elastic moduli of 2D materials via a very simple approach, based upon which the elastic moduli can be characterized via a new technique, like Raman spectroscopy.

中文翻译：

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一种从凸出膜的中心应变表征二维材料弹性模量的创新方法

独立式二维材料本质上处于粘合边界条件下，而不是通常假设的夹紧边界条件下，并且压力膨胀测试中的膜变形实际上与松弛膜的变形相似。根据给定压力下膨胀膜的中心应变，提出了一种新的独立式二维材料的膨胀测试模型，基于该模型，可以通过简单的测试方法正确表征二维材料的弹性模量。在这种方法中，不使用复杂的压力加载和测量系统，而是将安装在带有圆孔的基板上的二维材料简单地放入真空室中，并且可以通过拉曼光谱测量的中心应变来表征材料的模量。此外，采用有限元建模（FEM）来验证本工作中提出的模型的有效性。本方法可以为通过非常简单的方法有效表征二维材料的弹性模量提供有用的指导，在此基础上可以通过拉曼光谱等新技术来表征弹性模量。