Page 169 - Mechanical design of microresonators _ modeling and applications

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Microbridges: Lumped-Parameter Modeling and Design

168 Chapter Four
bridge

anchor anchor

substrate

Figure 4.1 Microbridge of constant rectangular cross-section.

z

anchor
x
θz, Mz

uz, Fz
uy, Fy
θx, Mx
ux, Fx
y θy, My
anchor
microbridge

Figure 4.2 Generic microbridge with degrees of freedom at its centroid.

7
chemical sensing purposes by Dufour and Fadel, nonlinear behavior
8
above critical points (anharmonic motions) by Ayela and Fournier, or
torsional resonance by Plotz et al. 9
Another class of microbridge applications targets the RF domain
with MEMS devices such as capacitive switches, filters, or variable/
10
tunable capacitors as reported by Yao et al.; Peroulis, Pacheco, and
12
11
Katehi; or Park et al.; to cite just a very small sample of the extended
literature that has been dedicated to this topic. More details, based on
a wide variety of studied examples of RF MEMS applications, are given
14
13
in Rebeiz whereas Madou presents several micoresonator imple-
mentations, including the microbridge configuration that is the subject
of this chapter.
The generic configuration sketched in Fig. 4.2 highlights the
6 degrees of freedom (three translations and three rotations) which are

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