MEMS Nano stage Lecture 1 and 2: Introduction, motivation Designed at IIT Bombay and course contents ME 645: MEMS: ME 645: MEMS: Design, Fabrication Design Fabrication Design Fabrication Design, Fabrication and Characterization and Characterization P.S. Gandhi P.S. Gandhi Mechanical Engineering Mechanical Engineering IIT Bombay IIT Bombay PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in What are MEMS? What are MEMS? � MEMS refer to miniature MEMS refer to miniature mechatronic mechatronic systems bulk fabricated using Very Large systems bulk fabricated using Very Large Scale Integration (VLSI) technology Scale Integration (VLSI) technology � Techniques and processes to design and Techniques and processes to design and create miniature systems create miniature systems � Miniature embedded systems Miniature embedded systems PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in 1
Sense for scale? Sense for scale? Decrease in length Interest for MEMS Interest for MEMS 1 μ m 0.1mm 1mm 1cm 1m 1km 10nm 100 μ m -Your height -Small screw -Spacing of -Hair size -Virus -Distance bet thread CD/DVD -Paper -Electron rails -Resolution of tracks, HD thickness beam -Meter scale steel ruler drives wavelength -light li ht -X ray wavelength -soap bubble � No of components on No of components on pentium pentium chip? chip? � How these are made?? How these are made?? PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in Motivation Motivation Why study MEMS?? Why study MEMS?? MEMS benefits MEMS benefits � Micro size systems Micro size systems � Higher sensitivity Higher sensitivity � Less energy withdrawal from application Less energy withdrawal from application � Decreased cost of production: bulk processing Decreased cost of production: bulk processing � Many new features and products previously Many new features and products previously unthought unthought of can be possible of can be possible � Combination of MEMS with other branches: Combination of MEMS with other branches: MEMS � futuristic Example optical MEMS, Bio Example optical MEMS, Bio- -MEMS futuristic PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in devices devices 2
MEMS Applications MEMS Applications Accelerometers and Gyroscopes Accelerometers and Gyroscopes - Automobile air bags Automobile air bags Automobile air bags Automobile air bags - Inertial navigation systems, Inertial navigation systems, autonomous aircrafts, autonomous aircrafts, segway egway, one wheel bike , one wheel bike Working Principle Based on capacitive sensing Based on capacitive sensing for microcombs PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in MEMS Applications MEMS Applications Bio- Bio -MEMS Sensors, chemical sensors MEMS Sensors, chemical sensors Cantilever based Cantilever based Cantilever based Cantilever based � Concept: cantilever structure with antigen Concept: cantilever structure with antigen � Effects corresponding bacteria come in Effects corresponding bacteria come in contact: contact: � Change in mass Change in mass � frequency frequency � Deflection due to repulsive forces Deflection due to repulsive forces p � Detection of bacteria by Detection of bacteria by � Optical Optical � Capacitive Capacitive � Other techniques like Other techniques like PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in resonance frequency measurement resonance frequency measurement 3
MEMS Applications MEMS Applications Deskjet Deskjet Printer Printer Deskjet printer cartridge: Deskjet Deskjet printer cartridge: Deskjet printer cartridge: printer cartridge: � Concept: resistive heating leading to Concept: resistive heating leading to formation of bubble that pushes the ink out formation of bubble that pushes the ink out from a from a microhole microhole as shown as shown Wire contact 160 μ m ink PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in Nozzles on printer cartridge MEMS Applications MEMS Applications Optical fiber switching Optical fiber switching Optical switch Optical switch p - Concept: use a Concept: use a micromirror micromirror and and selectively direct input light to various selectively direct input light to various output lines output lines Input fiber electrode Output fibers PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in 4
MEMS Applications MEMS Applications Digital Digital Light Processing (DLP) Light Processing (DLP) DLP Chip: DLP Chip: p - Concept: use thousands of individually Concept: use thousands of individually actuated actuated micromirrors micromirrors and selectively and selectively project light on each pixel project light on each pixel electrode PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in Micro Micro- - mirror mirror � Comb C C Comb b b Drive Drive Courtesy: Dr V . Milanovic Adriatic Research Institute PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in 5
MEMS Applications MEMS Applications Microfluidic Microfluidic Devices Devices Microfluidic Microfluidic channels for: channels for: - Realizing biosensors discussed before: - Realizing biosensors discussed before: Lab Lab- -on on- -chip chip - Reactors at Reactors at microscale microscale - Microturbines - Microturbines - Microheat - Mi Mi Microheat exchangers h h t t exchangers h - - Microcryocoolers Microcryocoolers - - Cell culture investigation Cell culture investigation - Electro transport - Electro transport PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in MEMS Applications MEMS Applications Micromechanisms Micromechanisms Mechanisms for various purposes including Mechanisms for various purposes including p p p p g g - - Nanopositioning Nanopositioning and and nanomanipulation nanomanipulation: : future HDDs, future HDDs, biocells biocells - - Mechanical logic Mechanical logic gates gates - - Mirror manipulation Mi Mi Mirror manipulation i i l ti l ti - Accelerometer - Accelerometer PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in 6
Flexure Mechanism Flexure Mechanism Concept � These mechanisms are These mechanisms are very useful at MEMS scale very useful at MEMS scale – No friction (no rubbing – N No friction (no rubbing N f i ti f i ti ( ( bbi bbi Parasitic error components) components) – Very high positioning Very high positioning accuracy possible accuracy possible � Used in many devices Used in many devices MEMS Nano stage Designed at IIT Bombay D i d t IIT B b PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in More MEMS devices More MEMS devices � Other micro Other micro- -sensors: sensors: � Pressure sensor Pressure sensor � Vibrating gyroscope Vibrating gyroscope � Bio Bio- -MEMS sensors: DNA chips, “lab on chip” MEMS sensors: DNA chips, “lab on chip” � Micro actuators Micro actuators And many more � Comb actuators, micro Yet to come… Comb actuators, micro- -motors motors � Thermal actuators Thermal actuators Thermal actuators Thermal actuators � Piezo Piezo- -actuators actuators � Micro Micro- -gears, micro gears, micro- -engines engines � Micro Micro- -fluidic systems: fluidic systems: drug delivery drug delivery: smart pill : smart pill � Grating light valve (GLV display) Grating light valve (GLV display) � Digital optical switches PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in Digital optical switches 7
Course outline Course Contents Course Contents � In this course, we will learn how to realize In this course, we will learn how to realize hi hi ill l ill l h h li li � these applications and innovate new ones these applications and innovate new ones � Introduction to MEMS: Motivation, history Introduction to MEMS: Motivation, history � and current status and current status and current status and current status � MEMS: Fabrication MEMS: Fabrication � – Conventional MEMS fabrication using VLSI Conventional MEMS fabrication using VLSI technology technology PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in – Nonconventional fabrication Nonconventional fabrication Course outline Conventional (VLSI ) Conventional (VLSI ) Fabrication processes Fabrication processes � Lithography: patterning Lithography: patterning � Chemical etching Chemical etching � Isotropic Isotropic Material removal � Anisotropic Anisotropic � Plasma etching: RIE Plasma etching: RIE � Oxidation Oxidation � Sputtering Sputtering Material deposition � Chemical vapor deposition (CVD) Chemical vapor deposition (CVD) � Electroplating Electroplating � Surface micromachining Surface micromachining PRASANNA S GANDHI gandhi@me.iitb.ac.in PRASANNA S GANDHI gandhi@me.iitb.ac.in � LIGA LIGA 8
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