ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Electrostatic MicroactuatorsOutlineReference listTo Explore FurtherMajor applicationsTypes of Electrostatic MAsWorking1Working (cont.)1Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Fabrication2Fabrication (cont.)2Slide 17Slide 18Slide 19Some Pictures3Some Pictures (cont.)4A Typical Example5A Typical Example (cont.)5LimitationsManufacturersECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Electrostatic MicroactuatorsPrepared by:Yashodhan TarteDept. of Electrical and Computer Engineering Utah State UniversityE: [email protected] ; T: (435)797-2845 3/11/200501/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline –Reference list–To Explore Further–Major Applications–Types of Electrostatic MAs–Working–Fabrication–Some Pictures–A Typical Example–Limitations–Manufacturers01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list1. Travel Range Extension of a MEMS Electrostatic Microactuator by D Piyabongkarn, Y Sun, R Rajamani, A Sezen, and B J Nelson. IEEE Transactions on Control Systems Technology, Vol. 13, No. 1, January 20052. A DRIE Comb-Drive Actuator With Large, Stable Deflection Range for Use as an Optical Shutter by John D. Grade, Kevin Y. Yasumura, and Hal Jerman, Iolon, Inc., San Jose, CA, USA3. University of Minnesota, Minneapolis4. Micromanipulation with Cilia Arrays5. Mechatronics of Electrostatic Microactuators for Computer Disk Drive Dual-Stage Servo Systems by Yunfeng Li and Roberto Horowitz. IEEE/ASME Transactions on Mechatronics, Vol. 6, No. 2, June 200101/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To Explore Further•This presentation gives a brief idea about electrostatic microactuators. So if you want to know more about this topic, you can try searching IEEE Xplore where you can find about current research going in this field.•Another type of MEMS actuator is electromagnetic microactuators. You may also want to explore them.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Major applications •Optical switching•Hard disk drive head motion •Manipulation of subcellular structures within biological cells•Microassembly of hybrid MEMS devices•Manipulation of large molecules such as DNA or proteins01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Types of Electrostatic MAs•Comb-drive •Parallel-plate01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Working1•The actuation principle behind parallel-plate electrostatic microactuators is the attractive force of two oppositely charged plates by applying a voltage between them.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Working (cont.)101/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Working (cont.)1•The comb-drive-type electrostatic microactuator has a large numbers of fine interdigitated “fingers” to generate the actuated force. •A comb drive that is actuated by a parallel-plate field at each finger pair is called a “transverse” comb drive. •The movable plate and movable finger are suspended by mechanical elastic members.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Working (cont.)1•Solid model of a two axis microactuator:01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Working (cont.)1•One axis comb drive model (offset):01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12Working (cont.)1•In the above figure x is the displacement of the movable fingers from the equilibrium position.•This comb drive is said to be “offset” since the distance x1 is much smaller than the distance x2.•Each gap between adjacent fingers has a specific capacitance.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13Working (cont.)1•For instance, C1 and C2 can be calculated by the following:where Kd = dielectric constant for the material, ε = permittivity of free space, and A = overlapping area of each finger pair.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14Working (cont.)1•The electrostatic force on the movable comb fingers is given bywhere N = number of parallel capacitor pairs, and V = applied actuation voltage.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-15Fabrication2•The following slides show the fabrication process of an electrostatic microactuator for optical shutter (shown below) application.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-16Fabrication (cont.)2•Etch shallow cavity in carrier wafer to create future movable areas.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-17Fabrication (cont.)2•Fusion bond device wafer to carrier; polish to final thickness.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-18Fabrication (cont.)2•Oxidize; open contact holes; deposit and pattern pad holes.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-19Fabrication (cont.)2•DRIE (deep reactive ion etching) etch through device wafer.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-20Some Pictures3•A close up of an electrostatic microactuator01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-21Some Pictures (cont.)4•A cut section of an organic thermal and electrostatic microactuator:01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-22A Typical Example5•IBM’s electrostatic microactuator mounted on an integrated lead suspension of hard disk drive head:01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-23A Typical Example (cont.)5•IBM’s electrostatic microactuator parameters:Resonance frequency: 1.5 kHz +/-15%Damping coefficient: 0.015Stroke limit: +/- 1 µmGain: 2 G/VMaximum voltage: +/-40V01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-24LimitationsApart from advantages of high performance andlow cost, these microactuators have somelimitations also:•In
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