ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Micro Electro-Mechanical Systems (MEMS) sensorsOutlineReference listTo explore further (survival pointers of web references etc)OverviewOverview - AccelerometerOverview - GyroscopeMajor ApplicationsMajor ApplicationsMajor AdvantagesPrinciple - AccelerometerSlide 12Principle - GyroscopeSlide 14Slide 15Devices Using MEMS sensorsMajor SpecificationsLimitationsSlide 19MEMS Sensor ManufacturersECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Topic: Micro Electro-Mechanical Systems (MEMS) sensorsPrepared by: Andrew HallDept. of Electrical and Computer Engineering Utah State UniversityE: [email protected]/6/200901/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline –Reference list–Overview–Major applications–Basic working principle illustrated–Applications using MEMS–Major specifications–Limitations–MEMS sensors manufacturers01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list•Roos, Gina, ‘MEMS sensors: good medicine’, www.eetimes.com/news/design/showArticle.jhtml?articleID=205207022•Torrance, Randy, ‘MEMS-based inertial sensor is not your grandfather’s gyroscope’, EDN, 12/1/2008•Weinberg, Harvey, ‘MEMS (Micro Electro-Mechanical Systems) Technology, http://www.sensorland.com/HowPage023.html01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further (survival pointers of web references etc) •http://www.sensorland.com/HowPage023.html–Sensorland provides information on how the MEMS sensor works and how it has moved into common products.•http://www.sensorsmag.com/articles/0203/14/–Sensorsmag provides more information MEMS and other sensors.•http://en.wikipedia.org/wiki/MEMS–Basic information on MEMS.Overview•MEMS sensors are one of the smallest mass-produced, low g, low cost, dual axis accelerometers.•Two major uses of MEMS sensors:–Accelerometers–Gyroscopes01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Overview - Accelerometer•Acceleration causes deflection of the body of the sensor (proof mass) from its suspended centre location.•The proof mass is suspended by polysilicon springs above the substrate such that the MEMS structure can move in the X and Y axes. 01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Picture from: http://www.sensorland.com/HowPage023.htmlOverview - Gyroscope•MEMS gyroscopes use a vibrating structure to determine orientation instead of traditional rotating disk. •Using Coriolis acceleration the gyroscopes measure their angular rate.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Picture from: www.edn.com/article/CA6614434.html?title=Article&spacedesc=news&nid=392701/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Major Applications •Accelerometers in consumer electronics:–Cell phones–PC hard disk drives–Cameras–Computer peripherals–Wireless devices–Airbag systemsMajor Applications•Gyroscopes in:–Cars–Robotics–Computer peripherals–Wireless devices–Other applications requiring yaw detection.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Major Advantages•Small footprint•Mass producible•Sensitive to low g’s•Low Cost•Low Power•High Performance•Integration•Rugged01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Principle - Accelerometer•Proof mass has 32 sets of radial fingers that make up a capacitor with a pair of fixed plates.•Differential capacitance is measured from the fingers and plates using synchronous modulation/ demodulation techniques.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Picture from: http://www.sensorland.com/HowPage023.htmlPrinciple - Accelerometer•ADXL202 MEMS sensor block diagram is shown.•Pulse-width-modulation (PWM) proportional to acceleration is the output of this MEMS accelerometer.•A microcontroller is used to decode the PWM.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12Picture from: http://www.sensorland.com/HowPage023.htmlPrinciple - Gyroscope• •Image taken of a gyroscope MEMS from a camera shows how the gyroscope was similar to the accelerometer in basics.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13Image from: http://www.edn.com/article/CA6614434.html?title=Article&spacedesc=news&nid=3927Principle - Gyroscope•Vibrating structure is used instead of a traditional rotating disks to determine orientation.•Acceleration proportional to the object’s distance from the center of the disk known as the Coriolis acceleration is the principle behind MEMS sensor gyroscopes.•Gyroscope has two MEMS devices similar to accelerometer in them.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14Principle - Gyroscope•Orientation of two MEMS structures allows two-axis detection and improved Coriolis acceleration measurements.•MEMS device shown has onboard EEPROM for factory calibration eliminating the need for external end-user calibration.•External circuitry is needed to detect the capacitance changes and regulate the MEMS sensor outputs.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-15Devices Using MEMS sensors01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-16“ADI's two-axis accelerometer is used for tilt inclination measurement of the user's forearm in Omron's blood pressure monitor for the wrist.”“Suitable for oxygen concentrators, inhaled anesthetics and ventilators, Omron's D6F MEMS flow sensors can measure flow speed from 1 mm/s to 40 m/s.”Images from: www.eetimes.com/news/design/showArticle.jhtml?articleID=205207022Major Specifications•Sensitivity •Accuracy•Voltage•Designed measurement parameters•Response time•Temperature range of operation•IC package01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-17Limitations•Mechanical design of microscopic mechanical systems take time to understand.•Materials not well characterized mechanically.•Polysilicon’s mechanical properties
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