Mechatronics (II) Seminar: “Introduction to MEMS Devices And FEM based COMSOL Multiphysics “ Presented By: Farid, Alidoust Ali, Taghizadeh Department of Mechanical Enginereeing, Islamic Azad University – Tabriz Branch May 2011

/

Topics: Introduction to MEMS Devices Introduction to COMSOL Multiphysics A multiphysic problem Simulation in COMSOL /

MEMS Devices: Introduction Brief History Electromechanical Systems MEMS Current Applications Conclusion /

Introduction MEMS = Micro Electro Mechanical System Scales of MEMS  1 micro meter to 1 millimeter (10 -6 to m). MEMS rely on technologies of miniaturization. Manufactured onto semiconductor material Used to make sensors, actuators, accelerometers switches, and light reflectors Used in automobiles, aerospace technology biomedical applications, ink jet printers, wireless and optical communications /

Brief History(1) 1947 Invention of the Point Contact Transistor A transistor uses electrical current or a small amount of voltage to control a larger change in current or voltage. Transistors are the building blocks of computers, cellular phones, and all other modern electronics. In 1947, William Shockley, John Bardeen, and Walter Brattain of Bell Laboratories built the first point-contact transistor. The first transistor used germanium, a semiconductive chemical. It demonstrated the capability of building transistors with semiconductive materials. First Point Contact Transistor and Testing Apparatus (1947) /

Brief History(2) 1954 Discovery of the Piezoresistive Effect in Silicon and Germanium Discovered in 1954 by C.S. Smith. The piezoresistive effect of semiconductor can be several magnitudes larger than that in metals. This discovery showed that silicon and germanium could sense air or water pressure better than metal Many MEMS devices such as strain gauges, pressure sensors, and accelerometers utilize the piezoresistive effect in silicon. Strain gauges began to be developed commercially in Kulite was founded in 1959 as the first commercial source of silicon strain gages. An Example of a Piezoresistive Pressure Sensor [MTTC Pressure Sensor] /

Brief History(3) 1958 Invention - First Integrated Circuit (IC) Prior to the invention of the IC there were limits on the size of transistors. They had to be connected to wires and other electronics. An IC includes the transistors, resistors, capacitors, and wires. If a circuit could be made all together on one substrate, then the whole device could be made smaller In 1958, Jack Kilby from Texas Instruments built a "Solid Circuit“ on one germanium chip: 1 transistor, 3 resistors, and 1 capacitor. Texas Instrument's First Integrated Circuit [Photos Courtesy of Texas Instruments] /

Brief History(4) 1971 The Invention of the Microprocessor In 1971, Intel publicly introduced the world's first single chip microprocessor - The Intel 4004 It powered the Busicom calculator This invention paved the way for the personal computer The Intel 4004 Microprocessor [Photo Courtesy of Intel Corporation] Busicom calculator [Photo Courtesy of Intel Corporation] /

Brief History(5) 1979 HP Micromachined Inkjet Nozzle Hewlett Packard developed the Thermal Inkjet Technology (TIJ). The TIJ rapidly heats ink, creating tiny bubbles. When the bubbles collapse, the ink squirts through an array of nozzles onto paper and other media. MEMS technology is used to manufacture the nozzles. The nozzles can be made very small and can be densely packed for high resolution printing. New applications using the TIJ have also been developed, such as direct deposition of organic chemicals and biological molecules such as DNA Schematic of an array of inkjet nozzles Close-up view of a commercial inkjet printer head illustrating the nozzles [Hewlett Packard] /

Brief History(6) 1982 LIGA Process Introduced LIGA is a German acronym for X-ray lithography (X-ray Lithographie), Electroplating (Galvanoformung), and Molding (Abformung). In the early 1980s Karlsruhe Nuclear Research Center in Germany developed LIGA. It allows for manufacturing of high aspect ratio microstructures. It allows for manufacturing 3D microstructures. LIGA structures have precise dimensions and good surface roughness. LIGA-micromachined gear for a mini electromagnetic motor [Courtesy of Sandia National Laboratories] /

Brief History(7) Developments in the 1980's In 1988 the first rotary electrostatic side drive motor were made at UC Berkley. Design of this Side Drive motor is Based on Brushless DC motor Concept. By frequently Energizing opposite channels in stator, rotor absorb to nearest gear of stator and moves in an electrostatic field. First Rotary Electrostatic Side Drive Motor [Richard Muller, UC Berkeley] /

Brief History(8) 1993 Multi-User MEMS Processes (MUMPs) Emerges In 1993 Microelectronics Center of North Carolina (MCNC) created MUMPs: A foundry meant to make microsystems processing highly accessible and cost effective for a large variety of users A three layer polysilicon surface micromachining process For a nominal cost, MUMPs participants are given a 1 cm 2 area to create their own design. In 1998, Sandia National Labs developed SUMMiT IV (Sandia Ultra-planar, Multi-level MEMS Technology 4) This process later evolved into the SUMMiT V, a five-layer polycrystalline silicon surface micromachining process Two simple structures using the MUMPs process [MCNC] A MEMS device built using SUMMiT IV [Sandia National Laboratories] /

Brief History(9) Late 1990's, Early 2000's BioMEMS Scientists are combining sensors and actuators with emerging biotechnology. Applications include drug delivery systems insulin pumps (see picture) lab-on-a-chip (LOC) Glucometers neural probe arrays Insulin pump [Debiotech, Switzerland] /

Brief History(10) Micro-electronics and MEMS { Differences & Analogies } MEMS fabrication technology was developed based on micro-electronic techniques. However, there are differences between them. MEMS involves more materials than ME. MEMS has moving parts Unlike ME. ME: 2D structure; MEMS: 3D structure. ME: completely protected By packaging; MEMS: sensors is interfaced with outside environment. /

Electromechanical Systems functional block diagram. Electromechanical Systems /

MEMS(1) Materials Crystallography – Forms of Silicon Amorphous Polycrystalline Crystalline “Miller Planes” Miller Indices, Direction Examples Microstructure Fabrication

/ MEMS(2) Pattern definition Photolithography Deposition Oxidation, chemical-vapor deposition, ion implantation Removal Etching, evaporation -Structural layer -Sacrificial layer deposit pattern etch Microstructure Fabrication

/ Processing Techniques Deep Reactive Ion Etching (DRIE) Surface Laser Micromachining LIGA process – Lithography / Electroplating / Molding MUMPs SUMMIT process Microstructure Fabrication, Continued MEMS(3)

/ The advantages of MEMS devices include Size High sensitivity Low noise Reduced cost Batch Processing The applications for MEMS are so far reaching that a multi-billion dollar market is forecast. Key industry applications include transportation, telecommunications and healthcare. MEMS(4)

/ MEMS(5) Worldwide MEMS Markets (in Millions of $) Microfluidics Optical MEMS RF MEMS39249 Other actuators Inertial sensors Pressure sensors Other sensors Total Worldwide MEMS Market (2002 vs. 2007) MEMS Economy Growing UP !!

/ Current Applications(1) Accelerometers Micro Optical Electro Mechanical Systems (MOEMS) Digital Mirror Devices (DMD) used in Projection Devices Deformable mirrors Optical Switches Inkjet Print heads (Microfluidics) Pressure Sensors Gyrometers Magnetic heads for hard drives

/ Current Applications(2) Micro-arrayed biosensors Virus detection DNA Chip PCR (Polymerase Chain Reaction) Neuron probes (nerve stimulus/repair) Retina Implants Micro Needles Micro Fluidic Pumps Insulin Pump (drug delivery) Biomedical

/ Current Applications(3) Micro and Radio Frequency (RF) Switches Array Antennas & RF Localization RFID Technologies Modern “bar-coding” system Data Storage Systems Detection systems

/ Conclusion Since the invention of the transistor, scientists have been trying to improve and develop new micro electro mechanical systems. The first MEMS devices measured such things as pressure in engines and motion in cars. Today, MEMS are controlling our communications networks. MEMS are saving lives by inflating automobile air bags and beating hearts. The applications and Growth for MEMS are endless !

/ COMSOL Multiphysics Introduction to Numerical Simulation FEM(Finite Element Method COMSOL Products Interfacing with Engineering Software's

/ Introduction to Numerical Simulation(1) We remember some Numerical Methods from Calculus ! In some Problems, complexity of analytical Methods enforce us to use numerical solutions Such problems that enforce us to use Numerical Methods: In Finitie Integral (Rectangular, trapezoidal, Simpson &…) Derivation (Finite difference, … ) Equation roots (Bisection, Newton, Levenberg Marquardt & …)

/ Introduction to Numerical Simulation(2) All Physical Problems can defined by Deferential Equations To forcast a physical problem we need to engage DEs !! Much Complex, The physical Problem Much Complex Differential Equations In Higher Order of DEs, it is so difficult or in some cases impossible to solve with conventional methods. So we use some numerical methods to overcome DEs. A Method mostly used to solve & simulate physical Problems, is FEM (FINITE ELEMENT METHOD)

/ FEM(Finite Element Method) The finite element method (FEM) (its practical application often known as finite element analysis (FEA) ) is a numerical technique for finding approximate solutions of partial differential equations (PDE) as well as of integral equations. The solution approach is based either on eliminating the differential equation completely (steady state problems), or rendering the PDE into an approximating system of ordinary differential equations, which are then numerically integrated using standard techniques such as Euler's method, Runge-Kutta, etc. Visualization of how a car deforms in an asymmetrical crash using finite element analysis 

/ Some COMSOL Products

/ COMSOL Import Modules COMSOL Script TM Interact with Matlab Add-ons to the CAD Import Module SolidWorks Online Module Pro/E Import Module CATIA V4 Import Module CATIA V5 Import Module Inventor Online Module VDA-FS Import Module

/ COMSOL Multiphysics Programming language and fast graphics COMSOL Script: Fully compatible with the MATLAB language All data types except objects Command line debugger, dbstop, dbstep, dbcont,... Fast 3D graphics using OpenGL acceleration (50 times faster than Matlab)

/ COMSOL Multiphysics Pre-defined multiphysics couplings

/ Now, Simulating A Multiphysics Problem : (Conjugate Heat Transfer in an air cooled Heatsink) In COMSOL !

/ Thermal and Structural Analysis of a heatsink (1)

/ Thermal and Structural Analysis of a heatsink(2)

/ Thermal and Structural Analysis of a heatsink(3) Now ; Simulating in Comsol Multiphysics

/ References: Gad-el-Hak, M. MEMS, Design and Fabrication, Second Edition. (2005) Lyshevski, S., MEMS and NEMS, CRC Press LLC. (2002) Maluf, N. and Williams, K., An Introduction to Micromechanical Systems Engineering, Second Edition, Artechouse, Inc. (2004) Microsytems, Same-Tec 2005 Preconference Workshop, July 25 &26, Taylor and Francis, MEMS Introductory Course, Sandia National Laboratories, June 13-15, What is MEMS technology? MEMS and Nanotechnology Clearinghouse.

Thanks for your Attention! /

Questions ?! /