Transcript Gilleo_MEMS-Nano4 - ET

4 Operation, mechanisms and
applications
•Ken Gilleo PhD
•ET-Trends LLC
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Motion (actuators)
• Actuators (“motors”)
POWER  Electrical (input)
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Thermal (usually from electrical)
Photonic (for MOEMS, OE)
• Sensors (output); usually electrical signals
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Change/output
is caused by
mechanical
motion/force
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Capacitance
Piezoresistive
Resonant beam
Electron tunneling
Photonic
Chemical
Biological/biochemical
TYPES
Actuator Classes
• Electrostatic/capacitive
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Linear comb drive
Rotary comb drive
Horizontal parallel plates
• Electromagnetic
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Linear
Rotary
Integrated coils or external field
Permanent or soft magnetic films
• Thermal
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Bimorph: dissimilar materials
Shape memory alloys
• Pneumatic/hydraulic
• Mechanical conversions/translations
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MEMS Engines
* very efficient
• Electrostatic;
• Thermal; easy to implement
• Electromagnetic, smaller
• Pneumatic
• Hydraulic
• Photoelectric (energy through fiber)
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*Surface area is
relatively high,
mass is very low;
surface effects are
important
Electrostatic (ES)
Charged
Charged
s
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l
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ES Unit
Anchor point
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Thermal Engines (T)
• Expansion
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Material, external; inkjet
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Bimorph beam - bending
• High force, moderate displacement
• Frequency limited by conductivity
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Bimorph Beam (Thermal)
off
Resistive
heater
on
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Electromagnetic
U of Wisconsin
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CalTech
MEMS Pumps
• Actuation Mechanisms
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Electrostatic
Thermal
Magnetic
Pneumatic
Piezoelectric
Ultrasonic
Debiotech STMicroelectronics insulin pump
Thermal Inkjet
• Direct Fluidic Actuation
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Bellows: Air Pump
Fluidic phase change
Electrohydrodynamic (EOF, electrophoresis, etc)
Direct fluidic actuation mechanisms
Sensors – the #1 Class
• Capacitance
Popular for
Accelerometers, mics, more
• Piezoresistive
• Resonant beam
• Electron tunneling
• Photonic
• Chemical
• Biological/biochemical
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Many
principles
Inertial Sensors (motion)
• Accelerometers
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Capacitor
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Resonant
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Multiple axis
ADI
• Gyroscopes
JPL
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ADI
Accelerometer/Gyros
• Automotive
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Sensing: crash, torque, vibration (well-being)
Navigation; GPS back-up
Active suspension
• Consumer
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Input device; computer, games, phones
Sports training, medical therapeutic
Alarms; burglar, seismic (earthquake)
Stabilization, camera
• Military
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Ordnance; guidance, condition, attack warning
Operator input/control
Aiming; gun, camera (stabilization)
• Industrial
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Sensing: vibration, tilt, direction, rate
Stabilization
Monitoring
Robotics; position, contact, feedback, etc.
ADI
Now owned by ADI
Dual-Axis Gyroscope
INERTIAL
Resonant
Accelerometers
3-Axis Accelerometer
Z-Axis Gyroscope
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Accelerometer Applications
Automotive
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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
Consumer
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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
Industrial/Scientific/Military
• 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
Automotive
Pressure
Sensors
Injector Pressure Sensor
Fuel Pressure Sensor
• Pressure Sensors
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Fuel
Tire
Manifold
Injector
AC
Mass air
Break
Fuel vapor
Oil
AC Pressure Sensor
Pressure Sensors
Thin
diaphragm
• Transducers
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Piezoresistor
Capacitor
Resonant beam
Internal ref.
pressure
Transducer
Vacuum
Resonating beam (F1)
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Resonating beam is now
under tension; (F2)
Chemical Sensors
Reactive surface
adsorbs gases
Readily detects H2, CO,
Alcohols, Hydrocarbons
i
Heater
Chem-sensor gate; adsorbing metal like Pd
Vs
Adsorption
lowers
threshold
voltage since
a dipole is
induced.
Vd
Chem-FET
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Mechanical Transfer
• Gears
• Wheels
• Levers
• Rackets
• Shuttles; walking
beams
• Hinge & lock
• Articulated beams
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Power 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 Extractors
Typically utilize machine mechanical vibrations
C1
C2
Changing capacitor
plate spacing
generates power;
reverse damper.
C2 an be replaced
with a magnet.
Machines produce mostly 1 KHz to 5 KHz vibrations
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Power MEMS
• Chemical fuel to:
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Mechanical rotation, reciprocation, etc.
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Fluid or gas pumping force
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Electrical (fuel cell)
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Thrust; rocket
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Mechanical
10 to 100 watts
100 K to
1-million RPM
Electrical (turbo-generator)
• Photonic to electrical (really just a converter)
• Mechanical, electrical to chemical (battery)
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Gas Turbine
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TI MOEMS: DLP
on
off
Over 8-million parts
on
on
on
on
off
on
Ref. “Digital Light Processing TM for High-Brightness, High-Resolution Applications” Larry J. Hornbeck, Ti.com
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1,400,000 mirrors in one module
Texas
Instruments
DLPTM
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animation by kbg
Session 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
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