Observation of Pull-In Instability in Graphene Membranes under Interfacial Forces

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• 作者：Xinghui Liu ; Narasimha G. Boddeti ; Mariah R. Szpunar ; Luda Wang ; Miguel A. Rodriguez ; Rong Long ; Jianliang Xiao ; Martin L. Dunn ; J. Scott Bunch
• 刊名：Nano Letters
• 出版年：2013
• 出版时间：May 8, 2013
• 年：2013
• 卷：13
• 期：5
• 页码：2309-2313
• 全文大小：324K
• 年卷期：v.13,no.5(May 8, 2013)
• ISSN：1530-6992

文摘

We present a unique experimental configuration that allows us to determine the interfacial forces on nearly parallel plates made from the thinnest possible mechanical structures, single and few layer graphene membranes. Our approach consists of using a pressure difference across a graphene membrane to bring the membrane to within 10鈥?0 nm above a circular post covered with SiO_x or Au until a critical point is reached whereby the membrane snaps into adhesive contact with the post. Continuous measurements of the deforming membrane with an AFM coupled with a theoretical model allow us to deduce the magnitude of the interfacial forces between graphene and SiO_x and graphene and Au. The nature of the interfacial forces at 10鈥?0 nm separation is consistent with an inverse fourth power distance dependence, implying that the interfacial forces are dominated by van der Waals interactions. Furthermore, the strength of the interactions is found to increase linearly with the number of graphene layers. The experimental approach can be used to measure the strength of the interfacial forces for other atomically thin two-dimensional materials and help guide the development of nanomechanical devices such as switches, resonators, and sensors.

Keywords:

Graphene; interfacial forces; nanoelectromechanical systems; pull-in instability