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4 Operation, mechanisms and applications

•Ken Gilleo PhD•ET-Trends LLC

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Motion (actuators)Motion (actuators)• Actuators (“motors”)

Electrical (input) Thermal (usually from electrical)

Photonic (for MOEMS, OE)

• Sensors (output); usually electrical signals Capacitance Piezoresistive Resonant beam Electron tunneling Photonic Chemical Biological/biochemical

TYPES

POWER

Change/outputis caused bymechanicalmotion/force

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Actuator ClassesActuator Classes• Electrostatic/capacitive

Linear comb drive Rotary comb drive Horizontal parallel plates

• Electromagnetic Linear Rotary Integrated coils or external field Permanent or soft magnetic films

• Thermal Bimorph: dissimilar materials Shape memory alloys

• Pneumatic/hydraulic• Mechanical conversions/translations

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MEMS EnginesMEMS Engines

• Electrostatic; very efficient

• Thermal; easy to implement

• Electromagnetic, smaller

• Pneumatic

• Hydraulic

• Photoelectric (energy through fiber)

*Surface area is relatively high, mass is very low; surface effects are important

*Surface area is relatively high, mass is very low; surface effects are important

*

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Electrostatic (ES)Electrostatic (ES)

Charged

Charged

Anchor point

shuttle

ES Unit

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Thermal Engines (T)Thermal Engines (T)• Expansion

Material, external; inkjet

Bimorph beam - bending

• High force, moderate displacement

• Frequency limited by conductivity

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Bimorph Beam (Thermal)

Bimorph Beam (Thermal)

Resistive heater

off

onLow CTE

High CTE

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ElectromagneticElectromagnetic

U of WisconsinCalTech

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MEMS PumpsMEMS Pumps• Actuation Mechanisms

Electrostatic Thermal Magnetic Pneumatic Piezoelectric Ultrasonic

• Direct Fluidic Actuation Fluidic phase change Electrohydrodynamic (EOF, electrophoresis, etc) Direct fluidic actuation mechanisms

Debiotech STMicroelectronics insulin pump

Bellows: Air Pump

Thermal Inkjet

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Sensors – the #1 ClassSensors – the #1 Class

• Capacitance

• Piezoresistive

• Resonant beam

• Electron tunneling

• Photonic

• Chemical

• Biological/biochemical

Popular forAccelerometers, mics, more

Popular forAccelerometers, mics, more

Manyprinciples

Manyprinciples

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Inertial Sensors (motion)

Inertial Sensors (motion)

• Accelerometers Capacitor

Resonant

Multiple axis

• Gyroscopes

ADI

ADIJPL

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Accelerometer/GyrosAccelerometer/Gyros• Automotive

Sensing: crash, torque, vibration (well-being) Navigation; GPS back-up Active suspension

• Consumer Input device; computer, games, phones Sports training, medical therapeutic Alarms; burglar, seismic (earthquake) Stabilization, camera

• Military Ordnance; guidance, condition, attack warning Operator input/control Aiming; gun, camera (stabilization)

• Industrial Sensing: vibration, tilt, direction, rate Stabilization Monitoring Robotics; position, contact, feedback, etc.

ADI

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Now owned by ADI

3-Axis Accelerometer

Z-Axis Gyroscope

Dual-Axis Gyroscope

ResonantAccelerometers

INERTIALINERTIAL

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Accelerometer Applications

Accelerometer Applications

• ABS/Antiskid

• Airbag Deployment

• Anti-Rollover Detection

• Battery Disconnect

• Crash Alerting

• Dynamic Suspension

• Dynamic Ride Control

• Dynamic Cruise Control

• Electronic Park Brake

• Fleet Monitoring

• Fuel Shutoff

• Headlight Leveling

• Inertial Navigation – backup

• Misfire Detection

• Security/Antitheft

• Seatbelt Tensioning

• Stability Systems

• Tilt Sensing

• Tire Motion

• Tire Pressure

• Transmission

• Monitor Vehicle Performance

• Active Subwoofers• Ambulatory Training • Appliances • Binoculars• Blood Pressure Monitor • Camcorders Stabilizer• Digital Pens • Digital Cameras Stabilizer• Disk Drive Monitoring • Game Controllers Handheld GPS • Head Tracking Inertial Navigation • Laptop Anti-Theft • Laptop Drop Detection • Joysticks Mouse - 3D• Out-of-Balance Medical Devices • Sleep Monitor Pedometers • Sports Training – golf• Sports Training – fly cast• Sports Training – batting• Tilt Sensing • Virtual Reality I/O• Wearable Computing I/O

• Antenna Alignment

• Antenna Switches

• Construction Leveling

• Machine

• Health Equipment

• Tilt Sensing

• Fork Lift Positioning

• Marine Navigation

• Platform Leveling

• Seat Damping

• Seismic

• Gas Shutoff

• Satellite Dish Alignment

• Satellite Gyroscopes

• Ship mechanical monitoring

• Shock Sensing

• UAVs

• UMVs

• Vibration Monitoring

Industrial/Scientific/Military Automotive Consumer

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Fuel Pressure Sensor

Injector Pressure Sensor

• Pressure Sensors Fuel Tire Manifold Injector AC Mass air Break Fuel vapor Oil

AC Pressure Sensor

AutomotivePressure Sensors

AutomotivePressure Sensors

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Pressure SensorsPressure Sensors

• Transducers Piezoresistor Capacitor Resonant beam

Internal ref. pressure

Thin diaphragm

Transducer

Resonating beam (F1) Resonating beam is now under tension; (F2)

Vacuum

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Chemical SensorsChemical Sensors

Readily detects H2, CO, Alcohols, Hydrocarbons

Reactive surface adsorbs gases

i

Heater

Chem-sensor gate; adsorbing metal like Pd

Adsorption lowers threshold voltage since a dipole is induced.

Chem-FET

Vs Vd

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Mechanical TransferMechanical Transfer• Gears

• Wheels

• Levers

• Rackets

• Shuttles; walking beams

• Hinge & lock

• Articulated beams

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Power Device ClassesPower Device Classes

1. Extractors using ambient energy

2. Converters: energy-1 energy-2

3. Relays for power (not signal)

4. Power controllers (beyond relays)

5. Generators using fuel

1. Uses waste energy, 2. Uses generated energy

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Power ExtractorsPower ExtractorsTypically utilize machine mechanical vibrations

C1

C2

Changing capacitor plate spacing generates power; reverse damper.

Machines produce mostly 1 KHz to 5 KHz vibrations

C2 an be replaced with a magnet.

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Power MEMSPower MEMS• Chemical fuel to:

Mechanical rotation, reciprocation, etc.

Fluid or gas pumping force

Electrical (fuel cell)

Thrust; rocket

Mechanical Electrical (turbo-generator)

• Photonic to electrical (really just a converter)

• Mechanical, electrical to chemical (battery)

10 to 100 watts 100 K to 1-million RPM

10 to 100 watts 100 K to 1-million RPM

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Gas TurbineGas Turbine

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TI MOEMS: DLPTI MOEMS: DLPon off

Ref. “Digital Light Processing TM for High-Brightness, High-Resolution Applications” Larry J. Hornbeck, Ti.com

on

on

on

on

on

off

Over 8-million partsOver 8-million parts

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TexasInstrumentsDLPTM

1,400,000 mirrors in one module

1,400,000 mirrors in one module

animation by kbganimation by kbg

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Session SummarySession Summary

• Most MEMS are directly electrically powered

• Electrostatic is simplest; very popular

• Bimorph is ideal for no/low wear beams

• Many kinds of mechanical transfer

• Sensors will remain largest market

• Reliability issues on some, but not all MEMS