Micro piezo motors
•Transferir como PPTX, PDF•
1 gostou•998 visualizações
This presentation explains in brief how piezo motor works. It also displays different type of piezo motors. It consists of a comparison of Piezo Motors and Electromagnetic motors.
Recomendados
Mais conteúdo relacionado
Mais procurados
Mais procurados (20)
Semelhante a Micro piezo motors
Semelhante a Micro piezo motors (20)
Último
Último (20)
Micro piezo motors
- 2. PRINCIPLE OF OPERATION ■ Works on Inverse Piezoelectric effect ■ Piezoelectric effect: Potential difference created on certain materials due to mechanical stress. ■ Converse of the above effect: Mechanical stress created on materials due to potential difference.
- 4. Materials that exhibit Piezoelectricity ■ Quartz ■ Berlinite (AlPO4), a rare phosphate mineral that is structurally identical to quartz ■ Sucrose (table sugar) ■ Rochelle salt ■ Topaz ■ Tourmaline-group minerals ■ Lead titanate (PbTiO3). ■ PZT - Lead Zirconate Titanate.
- 6. Features of micromotor: 1. No friction element to reduce resolution due sub nanometer range. 2. Do not require use of any lubricant and thus are ideal for ultrahigh vacuum applications. 3. Resolution: 1μm to 100μm 4. Force capability: in orders of 1000s of N 5. Temperature range: -200C to 200C 6. Voltage range: from a few millivolts to 1000V 7. No wear and tear. 8. No magnetics field involved, and hence is not affected by it. 9. Acceleration of the range 10,000 g. 10.Response time of microseconds.
- 7. Comparison of piezo motor vs Electromagnetic motor Electromagnetic motor 1. Comparatively large size 2. Less accuracy in range of micrometers 3. Cannot hold position while power is off 1. Efficiency falls down when size is scaled down 2. Designing linear electromagnetic motor is comparatively difficult. Piezo motor 1. Size in order of micrometer 2. Accuracy in range of nanometers 3. High holding capability even if powered off 1. Efficiency remains same even if size of motor is less 2. Designing and manufacturing linear micro piezo motor is very simple
- 8. Bimorph piezoelectric actuator ■ Similar to bimetallic strip ■ Two sheets of piezo films of opposite polarities adhered together forms a bimorph ■ Voltage applied → One film lengthens, other shrinks ■ Cantilever bends
- 10. Basic shear bender structure •A sandwiched beam is modeled where a part of the core has been replaced by piezoelectric material. •The electric field is applied perpendicular to the poling direction, inducing a transverse shear strain. •This shear bender consist of a 100 mm long sandwiched cantilever beam. •The 2 mm thick core is sandwiched by two 8 mm thick aluminum layers. •The rigid foam core is partially replaced by a 10 mm long piezoceramic actuator.
- 11. Simulation result of piezo shear bender Boundary conditions for simulation: 1. The cantilever beam is fixed at the surfaces at z=0 2. A 20 V potential difference is applied between the top and bottom surfaces of the piezoceramic subdomain.
- 12. Types of micro motors 1. Electromagnetic motors 2. Electrostatic motors 3. Piezoelectric motors a) Inertia Driven b) Resonance Drive c) Piezo-walk Drive
- 13. Inertia Driven/ Stick Slip Motors: I In this, movement is generated by friction. A sawtooth signal of electric field makes piezoelectric material expand fast and contract slowly making the attached mass move to and fro. In multilayer actuators, a sliding element (inertia mass) attached with a spring force, creating frictional coupling between rod and inertia mass. Such motors are
- 15. Principle of rotation in ultrasonic motor
- 16. Rotation principle of Ultrasonic Motor 1. Voltage applied → shape of piezoelectric ceramics changes 2. Standing wave is created with modifications in input voltage signal 3. The stator metal touches the rotor only at each peak of a traveling wave 4. Each of that peak carries out elliptical movement 5. A rotor rotates in response to the influence of the elliptical movement 6. Direction of movement of this ellipse is a direction contrary to the direction which a traveling wave follows.
- 17. Piezo walk drive Multiple piezoelectric actuators make synchronous motion by repeating “release- clamp-move and clamp-release-move” steps to produce a movement. Each drive element is a piezoelectric bimorph that is electrically isolated and can be controlled independently. Deformation in length and bending direction of the bimorph element simultaneously causes the pressed slider to make a linear motion. This principle drives piezoelectric stepper motors.
- 19. Why Piezo motors? Fast response time, compact size, and self-locking at the rest position make piezoelectric motors suitable candidates for focusing, zooming, and optical image stabilization in cameras. Inertia- and resonant-drive types are used by camera manufacturers for lens moving mechanisms. Piezoelectric motors have been integrated into various fields as compact, fast responding, and magnetic insensitive, vacuum compatible, and high- precision actuators. As systems in medical and micro robotic fields requiring more complex and multi-tasking actuations, the need for these motors would be in demand.
- 20. References 1. Piezo motor design principles, an overview: http://www.pi- usa.us/pdf/Different_Piezo_Motor_Designs_Overview.pdf 2. Ultrasonic motor operating: https://www.youtube.com/watch?v=9F8qU5LaHXY 3. What is a piezo motor and how it works: https://www.youtube.com/watch?v=i-Dm-5EfSAk 4. V8 piezo motor with nanometer precision: https://www.youtube.com/watch?v=vcdJh-ELcRY 5. Ultrasonic precision piezomotor: http://www.piezo-motor.net/pdf/Piezo_Motor_White- Paper_Ultrasonic_Piezoelectric_Precision_Motor.pdf 6. Comsol tool for MEMS: https://www.comsol.com/models/mems-module/page/4 7. Ultrasonic piezomotor: https://en.wikipedia.org/wiki/Ultrasonic_motor http://ieeexplore.ieee.org/document/1535999/