Sensor Technologies and Applications K. Park September 19, 2008

October, 2007© Copyright 2007 Measurement Specialties, Inc.2 Sensors 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? 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? Pressure Temperature Position (linear/rotary/tilt) Vibration Humidity Force Optical Gas

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

October, 2007© Copyright 2007 Measurement Specialties, Inc.8 Pressure 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 Sensor Supply voltage V dd U out - Sensor Ground GND U out + P = 0 to 500 bar

October, 2007© Copyright 2007 Measurement Specialties, Inc.10 Temperature 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 Sensors Method: Contact vs. non-contact Package: Bead vs. discrete, probe

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

October, 2007© Copyright 2007 Measurement Specialties, Inc.15 Humidity Sensors Technology: Capacitive vs. resistive Normally combined with temperature sensors

October, 2007© Copyright 2007 Measurement Specialties, Inc.16 Force Sensors (Load cell) Measures impact or force Technology: Silicon gage, piezoelectric

October, 2007© Copyright 2007 Measurement Specialties, Inc.17 Piezo 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 Optics Optical LEDs and photo diodes SpO2 (Pulse Oximetry) Sensors Switches and proximity sensing

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

October, 2007© Copyright 2007 Measurement Specialties, Inc.20 Sensor Applications -Examples-

October, 2007© Copyright 2007 Measurement Specialties, Inc.21 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) 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 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 level Bosch KMT32B Cam shaft BOSCH, AB Elektronik GMR Torque sensor ZF Lenk, SSI KMT34 wiper Valeo KMT32B, KMR360 Air damper ZF Lemförder KMT32B, GMR ABS Philips, ContiTeves KMG10 Gear stick ZF Lemförder KMR360 door lock Brose KMT32B, KMR Air damper ZF Sachs MLS200 Trunk hood brose KMT32B Active steering Pabst, ZF Lenk KMT32B Applications (Automotive)

October, 2007© Copyright 2007 Measurement Specialties, Inc.24 Applications (Aerospace & Military) Piezo for sonar Vibration sensor for motion control Temperature

October, 2007© Copyright 2007 Measurement Specialties, Inc.25 Applications (Medical) Patient monitoring Healthcare (wearable and disposable)

October, 2007© Copyright 2007 Measurement Specialties, Inc.26 Applications (Medical) Vibration sensor for pacemaker Thermopile for ear thermometer

October, 2007© Copyright 2007 Measurement Specialties, Inc.27 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) 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) 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) Thermopile for medical phone Thermopile for microwave oven Piezo ultrasound sensor for pen digitizer

October, 2007© Copyright 2007 Measurement Specialties, Inc.31 Applications (Consumer) Low range pressure sensor (Altitude sensing)

October, 2007© Copyright 2007 Measurement Specialties, Inc.32 Applications (Transportation) WIM (weight in motion) Red light camera Vibration monitor for high speed train