Sensor Technologies and Applications

K. Park

September 19, 2008

Sensor Technologies and Applications

K. Park

September 19, 2008

October, 2007© Copyright 2007 Measurement Specialties, Inc. 2

Sensors and ActuatorSensors and ActuatorSensors and ActuatorSensors and Actuator

• Sensor is a device that converts a physical event to an electrical signal.

• Example – Human skin

• Actuator is a device that converts an electrical signal to a physical event.

• Example – Human muscle

October, 2007© Copyright 2007 Measurement Specialties, Inc. 3

Why Sensors? Why Sensors? Why Sensors? Why Sensors?

Automation = Sensor + Controller + Actuator

• Makes human life more comfortable and convenient

• Increases productivity and reduce manufacturing cost

• Improves reliability of automobiles and machines

• Successful “human-like-robot” development depends on sensor and actuator technology (and AI)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 4

What to Sense?What to Sense?What to Sense?What to Sense?

• Pressure

• Temperature

• Position (linear/rotary/tilt)

• Vibration

• Humidity

• Force

• Optical

• Gas

October, 2007© Copyright 2007 Measurement Specialties, Inc. 5

How to Sense?How to Sense?How to Sense?How to Sense?

Sensing Technologies:

• MEMS

• Piezoelectric

• Strain gage

• Semiconductor

• Capacitance or resistance

October, 2007© Copyright 2007 Measurement Specialties, Inc. 6

Sensors (examples)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 7

Pressure Sensor (Concept)Pressure Sensor (Concept)Pressure Sensor (Concept)Pressure Sensor (Concept)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 8

Pressure SensorsPressure SensorsPressure SensorsPressure Sensors

• Converts air or liquid pressure into a signal

• Technologies: MEMS, Piezoelectric, diaphragm with bonded strain gage

October, 2007© Copyright 2007 Measurement Specialties, Inc. 9

Pressure SensorPressure SensorPressure SensorPressure Sensor

Supply voltage Vdd

Uout-

Sensor Ground GND

Uout+ P = 0 to 500 bar

October, 2007© Copyright 2007 Measurement Specialties, Inc. 10

Temperature SensorsTemperature SensorsTemperature SensorsTemperature Sensors

Sensing Technologies:

• Thermistors (Thermally sensitive resistor) – NTC, PTC

• RTD (Platinum, Copper, Nickel)

• Thermocouples

• Thermopile

Thermocouple: Electric current flows in a closed circuit of two dissimilar metals if their two junctions are at different temperatures

Thermistor: thermally sensitive ceramic semiconductor which exhibits a change in resistance as the temperature changes

October, 2007© Copyright 2007 Measurement Specialties, Inc. 11

Temperature SensorsTemperature SensorsTemperature SensorsTemperature Sensors

• Method: Contact vs. non-contact

• Package: Bead vs. discrete, probe

October, 2007© Copyright 2007 Measurement Specialties, Inc. 12

Position SensorsPosition SensorsPosition SensorsPosition Sensors

• Converts linear motion, rotation, angle, tilt into a signal

• Technology: LVDT, RVDT, hall effect, MR, conductive liquid

October, 2007© Copyright 2007 Measurement Specialties, Inc. 13

Vibration SensorsVibration SensorsVibration SensorsVibration Sensors

• Vibration or acceleration

• Technology: MEMS, bonded gage, piezoelectric

October, 2007© Copyright 2007 Measurement Specialties, Inc. 14

LOWER ELECTRODE

-

ULTRA THIN POLYMER LAYER- Allows high polymer to substrate integrity

POLYMER SANDWICH

- Better thickness homogeneity- Optimum sensitivity

UPPER ELECTRODE- Thick porous material - Mechanical and chemical ruggedness- Acts as an atmospheric filter- No step coverage issues- Layer used for trimming Capacitance Change

- Polished stainless steel wafer

Humidity Sensor (Principle)Humidity Sensor (Principle)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 15

Humidity SensorsHumidity SensorsHumidity SensorsHumidity Sensors

• Technology: Capacitive vs. resistive

• Normally combined with temperature sensors

October, 2007© Copyright 2007 Measurement Specialties, Inc. 16

Force Sensors (Load cell)Force Sensors (Load cell)Force Sensors (Load cell)Force Sensors (Load cell)

• Measures impact or force

• Technology: Silicon gage, piezoelectric

October, 2007© Copyright 2007 Measurement Specialties, Inc. 17

Piezo FilmPiezo FilmPiezo FilmPiezo Film

• New sensing material

• Works as a sensor as well as actuator

• Various applications require invention

October, 2007© Copyright 2007 Measurement Specialties, Inc. 18

Photo OpticsPhoto OpticsPhoto OpticsPhoto Optics

• Optical LEDs and photo diodes

• SpO2 (Pulse Oximetry) Sensors

• Switches and proximity sensing

October, 2007© Copyright 2007 Measurement Specialties, Inc. 19

Gas SensorsGas SensorsGas SensorsGas Sensors

IR-Lamp

CO2 Molecule Other Molecules

IR Bandpass(gas filter) for CO2

thermopile detector

3.5 4.0 4.5 5.0 5.50

10

20

30

40

50

60

70

80

90

100G4NO

G1CO

G2CO2

G20Ref.

G5.1HC

G5HC

Tra

nsm

issi

on

in %

Wavelength in m

October, 2007© Copyright 2007 Measurement Specialties, Inc. 20

Sensor Applications

-Examples-

October, 2007© Copyright 2007 Measurement Specialties, Inc. 21

Applications (Automotive)Applications (Automotive)Applications (Automotive)Applications (Automotive)

Automotive is the largest market for sensors

Air flow (air quality)

Airbag (thermopile, accelerometer)

EPB (Electronic parking break, Tilt)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 22

Applications (Automotive)Applications (Automotive)Applications (Automotive)Applications (Automotive)

• Gear shaft position• CVT-gear box• CAM• Speed sensor• CAM• Reference position sensor• Gear box sensor• Control stick• Shift lock• Power window• Clutch sensor• Gear box sensor• Speedometer• Brake Pedal• Wiper position • Fan• Steering sensor • Steering Lock • Alternator• CVT-gear box

• Brake pedal• ESP- steering wheel sensor• Gear box • CAM• Break / Clutch Pedal• Power window protection• Central lock• Central lock• Sunroof position• Buckle switch• CAM• Crank• Ride height• Throttle position• Suspension control• Seat belt tension sensor

• Current sensor• Head light adjustment

• Pressure sensor• Exhaust feed back (EGR)• Pedal sensor (drive-by-wire)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 23

Fuel levelBosch

KMT32B

Cam shaftBOSCH, AB Elektronik

GMR

Torque sensor ZF Lenk, SSI

KMT34

wiperValeo

KMT32B, KMR360

Air damperZF LemförderKMT32B, GMR

ABSPhilips, ContiTeves

KMG10

Gear stickZF Lemförder

KMR360

door lockBrose

KMT32B, KMR

Air damperZF SachsMLS200

Trunk hoodbrose

KMT32B

Active steeringPabst, ZF Lenk

KMT32B

Applications (Automotive)Applications (Automotive)Applications (Automotive)Applications (Automotive)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 24

Applications (Aerospace & Applications (Aerospace & Military)Military)Applications (Aerospace & Applications (Aerospace & Military)Military)

Piezo for sonar Vibration sensor for motion control

Temperature

October, 2007© Copyright 2007 Measurement Specialties, Inc. 25

Applications (Medical)Applications (Medical)Applications (Medical)Applications (Medical)

• Patient monitoring• Healthcare (wearable and disposable)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 26

Applications (Medical)Applications (Medical)Applications (Medical)Applications (Medical)

Vibration sensor for pacemaker Thermopile for ear thermometer

October, 2007© Copyright 2007 Measurement Specialties, Inc. 27

Applications (Test)Applications (Test)Applications (Test)Applications (Test)

Accelerometers for vehicle and dummy crash testing

Load cells to measure passenger restraint systems

October, 2007© Copyright 2007 Measurement Specialties, Inc. 28

Applications (Industrial)Applications (Industrial)Applications (Industrial)Applications (Industrial)

Tilt sensor for tip over protection and leveling

Piezo switch counter for water meter

Piezo film for tamper protection

October, 2007© Copyright 2007 Measurement Specialties, Inc. 29

Applications (Consumer)Applications (Consumer)Applications (Consumer)Applications (Consumer)

Vibration sensor for motion control, humidity sensor for dryer

Piezo for musical instrument pick up

Load cell for bathroom scale

October, 2007© Copyright 2007 Measurement Specialties, Inc. 30

Applications (Consumer)Applications (Consumer)Applications (Consumer)Applications (Consumer)

Thermopile for medical phone

Thermopile for microwave oven

Piezo ultrasound sensor for pen digitizer

October, 2007© Copyright 2007 Measurement Specialties, Inc. 31

Applications (Consumer)Applications (Consumer)Applications (Consumer)Applications (Consumer)

Low range pressure sensor(Altitude sensing)

October, 2007© Copyright 2007 Measurement Specialties, Inc. 32

Applications (Transportation)Applications (Transportation)Applications (Transportation)Applications (Transportation)

WIM (weight in motion)

Red light camera

Vibration monitor for high speed train