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Asymptotics of some nonlinear eigenvalue problems modelling a MEMS Capacitor. Part II: multiple solutions and singular asymptotics

Published online by Cambridge University Press:  22 December 2010

A. E. LINDSAY
Affiliation:
Department of Mathematics, University of British Columbia, Vancouver, British Columbia, V6T 1Z2, Canada email: [email protected], [email protected]
M. J. WARD
Affiliation:
Department of Mathematics, University of British Columbia, Vancouver, British Columbia, V6T 1Z2, Canada email: [email protected], [email protected]

Abstract

Some nonlinear eigenvalue problems related to the modelling of the steady-state deflection of an elastic membrane associated with a Micro-Electromechanical System capacitor under a constant applied voltage are analysed using formal asymptotic methods. These problems consist of certain singular perturbations of the basic membrane nonlinear eigenvalue problem Δu = λ/(1 + u)2 in Ω with u = 0 on ∂Ω, where Ω is the unit ball in 2. It is well known that the radially symmetric solution branch to this basic membrane problem has an infinite fold-point structure with λ → 4/9 as ϵ ≡ 1 − ||u|| → 0+. One focus of this paper is to develop a novel singular perturbation method to analytically determine the limiting asymptotic behaviour of this infinite fold-point structure in terms of two constants that must be computed numerically. This theory is then extended to certain generalisations of the basic membrane problem in the N-dimensional unit ball. The second main focus of this paper is to analyse the effect of two distinct perturbations of the basic membrane problem in the unit disk resulting from either a bending energy term of the form −δΔ2u to the operator, or inserting a concentric inner undeflected disk of radius δ. For each of these perturbed problems, it is numerically shown that the infinite fold-point structure for the basic membrane problem is destroyed when δ > 0, and that there is a maximal solution branch for which λ → 0 as ϵ ≡ 1 − ||u|| → 0+. For δ > 0, a novel singular perturbation analysis is used in the limit ϵ → 0+ to construct the limiting asymptotic behaviour of the maximal solution branch for the biharmonic problem in the unit slab and the unit disk, and for the annulus problem in the unit disk. The asymptotic results for the bifurcation curves are shown to compare very favourably with full numerical results.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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References

[1]Cassani, D.Marcos do Ó, J. & Ghoussoub, N. (2009) On a fourth-order elliptic problem with a singular nonlinearity. J. Adv. Nonlinear Stud. 9, 177197.Google Scholar
[2]Cowan, C.Esposito, P.Ghoussoub, N. & Moradifam, A. The critical dimension for a fourth-order elliptic problem with singular nonlinearity. Arch. Ration. Mech. Anal. (to appear).Google Scholar
[3]Cowan, C. & Ghoussoub, N. (2010) Estimates on pull-in distances in MEMS models and other nonlinear eigenvalue problems. SIAM J. Math. Anal. 42 (5), 19491966.Google Scholar
[4]Esposito, P. & Ghoussoub, N. (2008) Uniqueness of solutions for an elliptic equation modeling MEMS. Methods Appl. Anal. 15 (3), 341353.Google Scholar
[5]Esposito, P.Ghoussoub, N. & Guo, Y. (2007) Compactness along the branch of semi-stable and unstable solutions for an elliptic equation with a singular nonlinearity. Comm. Pure Appl. Math. 60 (12), 17311768.Google Scholar
[6]Esposito, P.Ghoussoub, N. & Guo, Y. (2010) Mathematical analysis of PDE modeling electrostatic MEMS. Courant Lecture Notes. 20, 318.Google Scholar
[7]Feng, P. & Zhou, Z. (2005) Multiplicity and symmetry breaking for positive radial solutions of semilinear elliptic equations modeling MEMS on annular domains. Electr. J. Differ. Equ. 146, 14. (electronic).Google Scholar
[8]Ghoussoub, N. & Guo, Y. (2006–2007) On the PDE of electrostatic MEMS devices: Stationary case. SIAM J. Math. Anal. 38 (5), 14231449.Google Scholar
[9]Grossi, M. (2006) Asymptotic behaviour of the Kazdan–Warner solution in the annulus. J. Differ. Equ. 223 (1), 96111.Google Scholar
[10]Guo, Y.Pan, Z. & Ward, M. J. (2005) Touchdown and pull-in voltage behaviour of a MEMS device with varying dielectric properties. SIAM J. Appl. Math. 66 (1), 309338.Google Scholar
[11]Guo, Z. & Wei, J. (2007) Symmetry of nonnegative solutions of a semilinear elliptic equation with singular nonlinearity. Proc. R. Soc. Edinburgh Sect. A 137 (5), 963994.Google Scholar
[12]Guo, Z. & Wei, J. (2008a) Infinitely many turning points for an elliptic problem with a singular nonlinearity J. Lond. Math. Soc. 78, 2135.Google Scholar
[13]Guo, Z. & Wei, J. (2008b) Asymptotic behaviour of touchdown solutions and global bifurcations for an elliptic problem with a singular nonlinearity. Comm. Pure. Appl. Anal. 7 (4), 765787.Google Scholar
[14]Guo, Z. & Wei, J. (2008c) Entire solutions and global bifurcations for a biharmonic equation with singular nonlinearity in 3. Adv. Diff. Equ. 13 (7–8), 743780.Google Scholar
[15]Guo, Z. & Wei, J. (2009) On a fourth-order nonlinear elliptic equation with negative exponent. SIAM J. Math. Anal. 40 (5), 20342054.Google Scholar
[16]Joseph, D. & Lundgren, T. (1972–1973) Quaslinear dirichlet problems driven by positive sources. Arch. Ration. Mech. Anal. 49, 241269.Google Scholar
[17]Kropinski, M. C.Lindsay, A. & Ward, M. J. Asymptotic analysis of localized solutions to some linear and nonlinear biharmonic eigenvalue problems. Submitted to Stud. Appl. Math. (to appear).Google Scholar
[18]Lagerstrom, P. (1988) Matched Asymptotic Expansions: Ideas and Techniques, Applied Mathematical Sciences, vol. 76, Springer-Verlag, New York.Google Scholar
[19]Lagerstrom, P. & Reinelt, D. (1984) Note on logarithmic switchback terms in regular and singular perturbation problems. SIAM J. Appl. Math. 44 (3), 451462.Google Scholar
[20]Lin, F. H. & Yang, Y. (2007) Nonlinear non-local elliptic equation modeling electrostatic actuation. Proc. Roy. Soc. Sect. A 463, 13231337.Google Scholar
[21]Lindsay, A. & Ward, M. J. (2008) Asymptotics of some nonlinear eigenvalue problems for a MEMS capacitor. Part I: Fold point asymptotics. Methods Appl. Anal. 15 (3), 297325.Google Scholar
[22]Pelesko, J. A. & Bernstein, D. H. (2002) Modeling MEMS and NEMS, Chapman Hall & CRC Press, London.Google Scholar
[23]Pelesko, J. A. (2002) Mathematical modeling of electrostatic MEMS with tailored dielectric properties. SIAM J. Appl. Math. 62 (3), 888908.Google Scholar
[24]Pelesko, J. A.Bernstein, D. & McCuan, J. (2003) Symmetry and symmetry breaking in electrostatic MEMS. In: Proceedings of Modeling and Simulation of Microsystems, San Fransisco, pp. 304307.Google Scholar
[25]Pelesko, J. A. & Driscoll, T. A. (2005) The effect of the small aspect ratio approximation on canonical electrostatic MEMS models. J. Eng. Math. 53 (3–4), 239252.Google Scholar
[26]Popovic, N. & Szymolyan, P. (2004a) A Geometric analysis of the lagerstrom model problem. J. Differ. Equ. 199 (2), 290325.Google Scholar
[27]Popovic, N. & Szymolyan, P. (2004b) Rigorous asymptotic expansions for Lagerstrom's model equation – a geometric approach. Nonlinear Anal. 59 (4), 531565.Google Scholar
[28]Wei, J. & Ye, D. (2010) On MEMS equations with fringing fields. Proc. Am. Math. Soc. 139 (5), 16931699.Google Scholar