The Effect of Curvature of Microbeam and Electrode on the Snap-Through and Pull- In Instabilities

Document Type : Research Article

Authors

Mechanical Engineering, Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

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.

Keywords

Main Subjects


[1]M.I. Younis, MEMS linear and nonlinear statics and dynamics, Springer Science & Business Media, 2011.
[2]Y. Fu, J. Zhang, Electromechanical dynamic buckling phenomenon in symmetric electric fields actuated microbeams considering material damping, Acta mechanica, 215(1-4) (2010) 29-42.
[3]J. Zhang, Y. Fu, Pull-in analysis of electrically actuated viscoelastic microbeams based on a modified couple stress theory, Meccanica, 47(7) (2012) 1649- 1658.
[4]Y. Fu, J. Zhang, R. Bi, Analysis of the nonlinear dynamic stability for an electrically actuated viscoelastic microbeam, Microsystem technologies, 15(5) (2009) 763-769.
[5]Y. Fu, J. Zhang, Nonlinear static and dynamic responses of an electrically actuated viscoelastic microbeam, Acta Mechanica Sinica, 25(2) (2009) 211-218.
[6]G. Rezazadeh, A. Tahmasebi, M. Zubstov, Application of piezoelectric layers in electrostatic MEM actuators: controlling of pull-in voltage, Microsystem technologies, 12(12) (2006) 1163-1170
[7]H. Moeenfard,  M.T.  Ahmadian,  Analytical closed form model for static pull-in analysis in electrostatically actuated torsional micromirrors, Journal of Mechanical Science and Technology, 27(5) (2013) 1443-1449.
[8]G. Hu, W. Liu, Nano/micro-electro mechanical systems: a patent view, Journal of Nanoparticle Research, 17(12) (2015) 465.
[9] V.K. Varadan, K.J. Vinoy, K.A. Jose, RF MEMS and their applications, John Wiley & Sons, 2003.
[10]  L.-D. Liao, P.C. Chao, C.-W. Huang, C.-W. Chiu, DC dynamic and static pull-in predictions and analysis for electrostatically actuated clamped circular micro-plates based on a continuous model, Journal of Micromechanics and Microengineering, 20(2) (2009) 025013.
[11] G.I. Taylor, The coalescence of closely spaced drops when they are at different electric potentials, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 306(1487) (1968) 423-434.
[12]  H.C. Nathanson, W.E. Newell, R.A. Wickstrom, J.R. Davis, The resonant gate transistor, IEEE Transactions on Electron Devices, 14(3) (1967) 117-133.
[13] L. Medina, R. Gilat, S. Krylov, Symmetry breaking in an initially curved micro beam loaded by a distributed electrostatic force, International Journal of Solids and Structures, 49(13) (2012) 1864-1876.
[14] J. Qiu, J.H. Lang, A.H. Slocum, A centrally- clamped parallel-beam bistable MEMS mechanism, in: Technical Digest. MEMS 2001. 14th IEEE International Conference on Micro Electro Mechanical Systems (Cat. No. 01CH37090), IEEE, 2001, pp. 353- 356.
[15]  Y. Zhang, Y. Wang, Z. Li, Y. Huang, D. Li, Snap- through and pull-in instabilities of an arch-shaped beam under an electrostatic loading, Journal of Microelectromechanical Systems, 16(3) (2007) 684- 693.
[16]   Y. Zhang, Y. Wang, Z. Li, Analytical method of predicating the instabilities of a micro arch-shaped beam under electrostatic loading, Microsystem Technologies, 16(6) (2010) 909-918.
[17] S. Park, D. Hah, Pre-shaped buckled-beam actuators: theory and experiments, Sensors and Actuators A: Physical, 148(1) (2008) 186-192.
[18] K. Das, R. Batra, Pull-in and snap-through instabilities in transient deformations of microelectromechanical systems, Journal of Micromechanics and Microengineering, 19(3) (2009) 035008.
[19] M.M. Zand, The dynamic pull-in instability and snap-through behavior of initially curved microbeams, Mechanics of Advanced Materials and Structures, 19(6) (2012) 485-491.
[20] H. Daneshpajooh, M.M. Zand, Semi-analytic solutions to oscillatory behavior of initially curved micro/nano systems, Journal of Mechanical Science and Technology, 29(9) (2015) 3855-3863.
[21] M.R. Salehi Kolahi, H. Moeinkhah, Non-linear vibration of curved microbeam under electrostatic actuation by using reduced order model and finite element simulation, Modares Mechanical Engineering, 17(12) (2018) 514-522. (In Persian)
[22] A.H. Ramini, Q.M. Hennawi, M.I. Younis, Theoretical and experimental investigation of the nonlinear behavior of an electrostatically actuated in- plane MEMS arch, Journal of Microelectromechanical Systems, 25(3) (2016) 570-578.
[23] A.R. Askari, M. Tahani, Size-dependent dynamic pull-in analysis of beam-type MEMS under mechanical shock based on the modified couple stress theory, Applied Mathematical Modelling, 39(2) (2015) 934-946.
[24]  M.I. Younis, H.M. Ouakad, F.M.  Alsaleem,  R. Miles, W. Cui, Nonlinear dynamics of MEMS arches under harmonic electrostatic actuation, Journal of Microelectromechanical Systems, 19(3) (2010) 647-656.
[25]  Y. Qian, D. Ren, S. Lai, S. Chen, Analytical approximations to nonlinear vibration of an electrostatically actuated microbeam, Communications in Nonlinear Science and Numerical Simulation, 17(4) (2012) 1947-1955.
[26]  Y. Fu, J. Zhang, L. Wan, Application of the energy balance method to a nonlinear oscillator arising in the microelectromechanical system (MEMS), Current applied physics, 11(3) (2011) 482-485.
[27]  R. Batra, M. Porfiri, D. Spinello, Vibrations of narrow microbeams predeformed by an electric field, Journal of Sound and Vibration, 309(3-5) (2008) 600-612.