Three-Dimensional Finite Element Method Simulation of Perforated Graphene Nano-Electro-Mechanical (NEM) Switches

• Main Authors: Mohd Amir Zulkefli, Mohd Ambri Mohamed, Kim S. Siow, Burhanuddin Yeop Majlis, Jothiramalingam Kulothungan, Manoharan Muruganathan, Hiroshi Mizuta
• Format: Article
• Language: English
• Published: MDPI AG 2017-07-01
• Series: Micromachines
• Subjects: nanoelectromechanical (NEM) switch; graphene; intact beam structure; perforated beam structure; finite element simulation (FEM); pull-in voltage characteristic; von Mises stress
• Online Access: https://www.mdpi.com/2072-666X/8/8/236

The miniaturization trend leads to the development of a graphene based nanoelectromechanical (NEM) switch to fulfill the high demand in low power device applications. In this article, we highlight the finite element (FEM) simulation of the graphene-based NEM switches of fixed-fixed ends design with beam structures which are perforated and intact. Pull-in and pull-out characteristics are analyzed by using the FEM approach provided by IntelliSuite software, version 8.8.5.1. The FEM results are consistent with the published experimental data. This analysis shows the possibility of achieving a low pull-in voltage that is below 2 V for a ratio below 15:0.03:0.7 value for the graphene beam length, thickness, and air gap thickness, respectively. The introduction of perforation in the graphene beam-based NEM switch further achieved the pull-in voltage as low as 1.5 V for a 250 nm hole length, 100 nm distance between each hole, and 12-number of hole column. Then, a von Mises stress analysis is conducted to investigate the mechanical stability of the intact and perforated graphene-based NEM switch. This analysis shows that a longer and thinner graphene beam reduced the von Mises stress. The introduction of perforation concept further reduced the von Mises stress at the graphene beam end and the beam center by approximately ~20–35% and ~10–20%, respectively. These theoretical results, performed by FEM simulation, are expected to expedite improvements in the working parameter and dimension for low voltage and better mechanical stability operation of graphene-based NEM switch device fabrication.