Lesson 1. Main applications of Microsystems technologies/Microelectromechanical systems (MST/MEMS). History of MEMS. Sensors and actuators. Inertial sensors, optical devices for telecommunication applications, micro mirrors and micro displays, micro resonators for radio-frequency (RF) applications, micro switches, cantilever micro sensors, biochemical sensors, micro pumps, micro robotics. Main types of micro actuators – electrostatic, thermal, magnetic, pneumatic. Role of miniaturization. Role of modeling.

 

Lessons 2-5. Materials used in micro devices. Crystallographic structure of silicon. Main fabrication processes. Main deposition methods-spinning, oxidation, evaporation, chemical vapor deposition, sputtering, electrodeposition, molding. Etching methods, wet and dry etching, reactive ion etching, deep reactive ion etching. Pattern transfer techniques, lithography, alignment. Integrated processes, surface micromachining, MUMPS process. Bulk micromachining, silicon on insulator (SOI) process, SCREAM. Packaging of micro devices.

 

Lesson 6. Detailed design. Critical dimensions, alignment, influence of fabrication process on the detailed design. Mask design principles, layout software. Examples of designs of microstructures fabricated using surface and bulk micromachining.

 

Lessons 7-10. Suspensions. Torsional springs. Guided, cantilever and double clamped beams. Calculations of stiffness of the suspension. Role of geometric nonlinearities. Simplified models of double-clamped beams with an axial stretching force. Folded suspension. Example of compliant mechanisms, motion transformers and amplifiers. Figures of merit of motion transformers.

 

Lesson 11. Methods of measurement of material properties in MEMS. Bulge test, indentation, indirect tension test, direct tension test. Choice of the testing method for material characterization. Role of residual stresses and methods of residual stress measurement.

 

Lesson 12-15. Main actuation principles. Electrostatic actuator. Spring-capacitor model. Equilibrium and stability, pull-in, operational range of the electrostatic actuator. Linear and rotational comb-drive actuator, tilting electrostatic actuator (micro mirror), electrostatically actuated micro beams. Dynamics of the electrostatic actuator. Scaling of the electrostatic actuator. Examples of the devices, scratch drive actuator, push-pull actuator.

 

Lesson 16. Magnetic actuators. Lorentz force, calculation of forces and torques, example of devices.

 

Lesson 17-18. Joule heating and thermal actuators. Actuators based on pre-curved U-shaped or V-shaped elements, bimorph actuators. Evaluation of operational range and efficiency of the actuator. Examples of applications. Scaling of the thermal actuator. Other actuation principles-pneumatic actuators, piezoelectric actuators, electroactive polymers based actuators. Modeling approaches. Figures of merits of micro actuators. Role of scaling and choice of the actuation approach.

 

 

Lesson 19. Damping mechanisms. Material damping and viscous air damping. Squeeze film damping. Squeeze number. Modeling approaches for squeeze film damping. Slide film damping model.

 

Lesson 20-21. Case studies. Micro accelerometer. Operational principles. Capacitive and piezoresistive sensing. Figures of merit. Noise.

 

Lesson 22. Case studies. Optical Mems and nanophotonic circuits. Challenges and Solutions. Figures of merit. Noise.

 

Lesson 23. Case studies. Resonant mass sensor. Figures of merit. Noise.