Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 8 2019 04 22 The Effect of Curvature of Microbeam and Electrode on the Snap-Through and Pull- In Instabilities The Effect of Curvature of Microbeam and Electrode on the Snap-Through and Pull- In Instabilities 2243 2260 3373 10.22060/mej.2019.15562.6157 FA Ehsan Akrami Nia Mechanical Engineering, Engineering, Ferdowsi University of Mashhad, Mashhad, Iran 0000-0003-4085-4564 Hamid Ekhteraei Toussi Mechanical Engineering, Engineering, Ferdowsi University of Mashhad, Mashhad, Iran 0000-0003-2609-8504 Journal Article 2018 12 31 Due to the pull-in instability, the sustainability of micro-electro-mechanical systems is vulnerable. One of the proposed mechanism to improve the stability of these systems is the use of curved microbeams. The curvature causes the snap-through phenomenon by which the microbeam moves to its second stable position. Despite the advantages of snap-through, sometimes it leads to unstable conditions. In order to use the merits of curved structure and avoid the snap-through effect, in the present study, the performance of a structure composed of curved electrode is investigated. By assuming the Euler-Bernoulli beam theory and based on the modified couple stress theory, the governing equation is obtained by using Hamilton’s principle. This equation is converted to a nonlinear ordinary differential equation by using the reduced-order model based on Galerkin procedure. The numerical solution is formulated and obtained by using the MATLAB software. The performance of the systems composed of curved microbeam and curved electrode are compared with each other, as well as with the systems made of straight elements. The results show that in cases where snap-through may cause unstable conditions, the use of curved electrode can result in more sustainable behavior in a wider range of position and voltage levels. Due to the pull-in instability, the sustainability of micro-electro-mechanical systems is vulnerable. One of the proposed mechanism to improve the stability of these systems is the use of curved microbeams. The curvature causes the snap-through phenomenon by which the microbeam moves to its second stable position. Despite the advantages of snap-through, sometimes it leads to unstable conditions. In order to use the merits of curved structure and avoid the snap-through effect, in the present study, the performance of a structure composed of curved electrode is investigated. By assuming the Euler-Bernoulli beam theory and based on the modified couple stress theory, the governing equation is obtained by using Hamilton’s principle. This equation is converted to a nonlinear ordinary differential equation by using the reduced-order model based on Galerkin procedure. The numerical solution is formulated and obtained by using the MATLAB software. The performance of the systems composed of curved microbeam and curved electrode are compared with each other, as well as with the systems made of straight elements. The results show that in cases where snap-through may cause unstable conditions, the use of curved electrode can result in more sustainable behavior in a wider range of position and voltage levels. https://mej.aut.ac.ir/article_3373_0084ae4bc24c0795d1e6a4f58444d39b.pdf