Seminar on Qualitative Theory of Differential Equations - Annalisa Iuorio (28.11.2019)
Thursday 2811.2019 at 14:00, Lecture room M/223
Annalisa Iuorio (RICAM Linz):
Singular Perturbation Analysis of a Regularized MEMS Model
Abstract:
Micro-Electro Mechanical Systems (MEMS) are defined as very small structures that combine electrical and mechanical components on a common substrate. Here, the electrostatic-elastic case is considered, where an elastic membrane is allowed to deflect above a ground plate under the action of an electric potential, whose strength is proportional to a parameter. Such devices are commonly described by a parabolic partial differential equation that contains a singular nonlinear source term. The singularity in that term corresponds to the so-called "touchdown" phenomenon, where the membrane establishes contact with the ground plate. Touchdown is known to imply the non-existence of steady state solutions and blow-up of solutions in finite time. In this talk we analyze a recently proposed extension of that canonical model, where such singularities are avoided due to the introduction of a regularizing term involving a small "regularization" parameter. Methods from dynamical systems and geometric singular perturbation theory, in particular the desingularization technique known as "blow-up", allow for a precise description of steady-state solutions of the regularized model, as well as for a detailed resolution of the resulting bifurcation diagram. The interplay between the two main model parameters is emphasized; in particular, the focus is on the singular limit as both parameters tend to zero. This is a joint work with Nikola Popovic and Peter Szmolyan.