Mechanics of Microsystems

Teacher: Professor David Elata


Week Topic Recitation
 1  Course overview and rules, short introduction to MEMS.
Overview of microfabrication processes: photolithography, patterning, etching, deposition, sacrificial layers, lift-off, deep wet and dry etching, DRIE.
Process flow SOI.
2 Electrostatics: electric field, electric displacement, boundary conditions. Electrostatic actuation, energy method, model of the parallel-plates actuator: charge and voltage control, stability. Tilt plate actuator.
3 Electrostatic actuation: comb-drive actuators. One-sided and double-sided actuators. Bifurcation of the symmetric parallel-plates system. Angular comb-drive.
4 Flexures. The Euler-Bernoulli beam equation. Clamped-Clamped beam suspensions. Nonlinear response of the clamped-clamped beam suspension.
5 Folded-beam suspension, Silicon as a mechanical material Electrostatic bifurcation of a single comb finger.
6 Fringing fields and levitation in comb-drives. Side pull-in. Introduction of layout tool.
7 Stresses in thin layers. Curling and buckling, passive test devices. Mid-term exam.
8 Thermoelastic actuation. Heat conduction in a 1-D bar. Bi-morph, hot-cold arm, and chevron actuators. Chevron actuator.
9 Electric fields in dielectric layers. Capacitive RF switch. Dielectric comb-drive.
 10 Piezoelectric Transduction. Direct and converse effects. Physical explanation. Transduction efficiency. 1D linear resonator.
11 Piezoelectric Transduction continued. Vibration of the cantilever beam.
 12  Electrostatic resonators. Quality factor. Ring and disk resonators and oscillators.  Dynamic response of the folded-beam suspension
 13  Dynamic response of electrostatic actuators. Discussion of advanced topics.  Review of course material.