Silicon Programming--Introduction to MEMS 1 Introduction to MEMS; energy domains; mechanical and fluidic devices

Silicon Programming--Introduction to MEMS 2 MEMS (Microelectromechanical systems) (Other commonly used terms: Microsystems (Europe); Microfluidics; Mechatronics (Japan) ) All these terms refer to "systems" incorporating electrical elements and elements from other domains into a "chip" or "integrated circuit". Both miniaturization and integration are usually implied. Another term commonly used is "SOC", which stands for "system on a chip".

Silicon Programming--Introduction to MEMS 3 Motivations for MEMS: -----space (area) savings -----power reduction (can we use batteries?) -----portability (reduced weight / power) -----reliability--because of integration -----economic savings--"mass produce" elements as VLSI chips are currently produced -----application of well-understood VLSI processing techniques to other domains

Silicon Programming--Introduction to MEMS 4 Application areas (a sampling) automotive systems -----environmental control / monitoring -----health care -----defense systems automated manufacturing Example applications (see, e.g., Analog Devices website, --airbags: change in acceleration (force) is translated into signal to deploy airbag --navigation and stabilization: micro gyroscopes provide a frame of reference in navigation and stabilization systems in cars, planes, etc. --”lab on a chip”: biological / chemical procedures can be carried out on one integrated chip (Lab on a Chip journal:

Silicon Programming--Introduction to MEMS 5 Area is INHERENTLY MULTIDISCIPLINARY (based on today's "disciplines") How old is this area? (~ 30 years) basic reference: K. Petersen, Silicon as a mechanical material, IEEE Proceedings 70 (5), May 1982,

Silicon Programming--Introduction to MEMS 6 Basic idea: IC's perform (electronic) calculations extremely well; I/O is NOT generally in the electrical domain--how can I/O elements (“sensors” and “actuators”, or "transducers")be integrated?

Silicon Programming--Introduction to MEMS 7 Energy Domains: 1. thermal--temperature, heat, heat flow, etc. 2. mechanical--force, pressure, ve;ocity, acceleration, position, etc. 3. chemical--concentration, material composition, reaction rate, etc. 4. magnetic--magnetic field intensity, flux density, magnetization, etc. 5. radiant--intensity, wavelength, polarizaion, phase, etc. 6. electrical--voltage, current, charge, etc.

Silicon Programming--Introduction to MEMS 8 Relation to IC's: Typical IC is built up of "layers" of material. These layers can be used to make other devices, e.g., cantilever beams for sensing and actuating Techniques for "machining" are those used in IC fabrication--how can they be used / modified to make devices usable in other domains?

Silicon Programming--Introduction to MEMS 9 Devices are generally divided into two classes according to processing required: a. "surface micromachining" (2.5D devices) uses “layers” b. "bulk micromachining" (true 3D devices)

Silicon Programming--Introduction to MEMS 10 examples: beams cantilever beams membranes ducts motors, movable parts

Silicon Programming--Introduction to MEMS 11 How can MEMS development make use of well-understood IC CAD capabilities? What extensions are needed for CAD for MEMS? Recall: 1. Predicting IC performance requires input from fabrication, design, and environment. 2. Tools for incorporating information from each of these domains are necessary for "rapid prototyping" which make many IC designs economically feasible.

Silicon Programming--Introduction to MEMS 12 Comparisons of Mechanical Properties (Petersen) PropertySiSiO 2 SteelAl Yield (10 10 dyne/cm 2 ) Hardness (kg/mm 2 ) Young's mod (10 12 dyne/cm 2 ) Density (gr/cm 3 ) Therm. cond (W/cm o C) Thermal exp (10 -6 / o C)

Silicon Programming--Introduction to MEMS 13 Tasks: Specify-Design-Simulate-Fab-Test-Maintain ===================================================================================== LEVELS||VIEWS ||Behavioral StructuralPhysical ===================================================================================== 4 ||Specifications, CPUs,Memory,Partitions ||Systems Switches, Complex ||MEMS ||Algorithms Data StructuresClusters ||Register TransfersALUs, Registers, Floorplans ||Electromechanical ||Components ||Boolean Equations, Gates, Flip-flops,Cells, ||FSMs, MechanicalSensors, ActuatorsModules ||Behavior ||Transfer FunctionsTransistors, Wires, Layout ||Contacts, Vias, Geometry ||Beams, Membranes, ||Holes, Grooves, ||Joints ====================================================================================