Piezo Electric Effect

here is a ppt presentation of piezoelectric current

1. Piezoelectric Current Submitted by: m Saqlain (2017-ch-271) sarmad ali (2017-ch-235) faizan ahmad (2017-ch-277) ali ahmad (2017-ch-263)

2. Introduction to pizeoelectrcity By M saqlain

3. Pizeoelectric current Piezo electric current The type of current which is generated by applying a stress on specific materials know as piezoelectric current Piezeoelectric effect The ability of material to generate an electric charge in response to apply mechanical stress

4. Types of piezoelectric effect Direct piezoelectric effect The type of effect in which elecetricv charge develop as a result of mechanical stress Converse piezoelectric effect The type of effect in which mechanical stress develop as a result of applying electric field

5. diagarame

6. pioezoelectric material; The type of material which has an ability to produce an electric current on applying mechanical stre4ss Example Quartz sucrose

7. Piezoelectric motor It is a type of electric motor that produce motion either linear or rotational based on the change in shape of a piezoelectric material when an electric field is applied known as piezo motor

8. Working principle The working principle piezo electric motor depend on converse piezo electric effect

9. objective To convert mechanical energy into electrical energy To get more precise value To increase efficiency of motor in industry

10. applicatiion It is used in production and detection of sound It is used in generation of electronic frequency It is used in generation of high voltage it is used in medical engineering It is used in flow control application

11. Advantage and disadvantage advantage They require very small size for producing very high torque Fast response time High resolution They are flexible disadvantahe Its life time is short It is handmade so it is difficult to control Its production is not on large scale expensive

12. Case study Industries used electric or DC motors for optical system but there is a problem of movement and adjustment in optical system for small changes and errors and defects are present. And also the problem of focus zoom and change of view.

13. Case study 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. Many camera manufacturers have piezoelectric motor solutions especially inertia- and resonant-drive types for lens moving mechanisms These all problem can be solve by using piezoelectric motor instead of DC motor.

14. Piezoelectric Actuators By: Sarmad ali

15. Actuators: An actuator is a component of a machine that is responsible for moving and controlling a mechanism or system, for example by opening a valve. An actuator requires a control signal and a source of energy.

16. Objective To convert an Electric signal into a Precisely controlled displacement

17. Characteristics Unlimited Resolution High Force Generation No wear and tear Low energy Consumption No magnetic fields Rapid Response

18. Working Principle Piezoelectric Effect When stress is applied on the quartz crystals then an electric charge is produced The Piezo actuators work on reverse piezoelectric effect. It uses the electric charge to create mechanical displacement or deformation The electrical field generates a torque over the electrical dipoles found in the structure of the material, which will be aligned along the field, producing in turn a change in the length of monocrystalline partitions.

19. Types Stack Actuators Piezo stack actuators offer low stroke and a high blocking force. Based upon the user’s requirements stack actuators can be either discrete or co-fired. Discrete stacks (high-voltage stack actuators) are composite structures made by stacking separately finished piezoelectric ceramic discs or rings and metal electrode foils with an adhesive. Operating voltages ranging from 500 V thru 1,000 V are typical.

20. Stripe Actuators A Stripe actuator, also called a bending actuator, is designed to produce a relatively large mechanical deflection in response to an electrical signal. This deflection offers a large stroke and a very limited blocking force when compared to a stack actuator.

21. Applications In precision knitting machines For auto focusing mechanism in microphone-equipped video cameras and mobile phones they are used in cryogenic and vacuum environments

22. Case Study

23. Solution  This was achieved by encapsulating the raw piezoelectric ceramic actuators between layers of flexible circuits, enabling An hermetical seal around the wafers - eliminating the moisture issue An electrical connection to the wafers - eliminating the need for solder The design to include features to ease mechanical integration Flat & flexible circuits - making sealing easy and repeatable

24. Piezoelectric transformers 2017-CH-277

25. OBJECTIVES: To convert mechanical pressure into electrical energy To reduce the cost of production of electrical energy To produce reliable method of production improve the performance of power electronic PCBAs

26. INTRODUCTION: Piezoelectric transformers, are basically energy converters. A magnetic transformer operates by converting electrical input to magnetic energy and then reconverting that magnetic energy back to electrical output. This mechanical conversion is achieved by a standing wave vibrating at a frequency equal to a multiple of the mechanical resonance frequency of the transformer body, which is typically in the range of 50 to 150 kHz.

27. WORKING PRINCIPLE: The operational principle is that the primary element or section of the transformer is excited by an electrical AC voltage, which induces a deformation of the joined structure. The deformation of the secondary element or section will generate a charge displacement and an electrical output voltage. And through the PT design (structure, section size, layer thickness), a desired voltage conversion can be achieved, matching a specific load and application.

28. ADVANTAGES: Electromechanical energy conversion No magnetic field generation, as well as immunity to magnetic fields. Low EMI prole, due to the nature of resonance converter and soft switching Potential high efficiency and power density. DISADVANTAGES: Best suited for constant resistive AC loads. Mechanical mounting of PT, without restricting the free mechanical movement. Low thermal conductivity of ceramics, limiting heat dissipation. Limited current carrying capacity, due to thin electrodes.

29. CASE STUDY

30. SOLUTION: PTS can be used to improve the performance of power electronic PCBAs(Printed circuit board) deployed in industrial systems and environments. At  Tempo Automation , the industry leader in high-quality, fast PCBA prototyping and low-volume production, it can accommodate piezoelectric transformers and other power electronics technology for industrial PCBAs.

31. Piezoelectric Sensor 2017CH263

32. Piezoelectric sensor: A  piezoelectric sensor  is a device that uses the  piezoelectric  effect to measure changes in pressure, acceleration, temperature, strain, or force by converting them to an electrical charge.

33. Working principle When a force is applied to a piezoelectric material, an electric charge is generated across the faces of the crystal. This can be measured as a voltage proportional to the pressure. There is also an inverse piezoelectric effect where applying a voltage to the material will cause it to change shape.

34. Characteristics: P iezoelectric sensors are not normally suitable for measuring static pressure. The output signal will gradually drop to zero, even in the presence of constant pressure. They are, however, sensitive to dynamic changes in pressure across a wide range of frequencies and pressures. This dynamic sensitivity means they are good at measuring small changes in pressure, even in a very high-pressure environment.

35. Applications : U sed in a wide range of industrial and aerospace applications where they’ll be exposed to high temperatures and pressures. They are often used for measuring dynamic pressure, for example in turbulence, blast, and engine combustion. Their sensitivity and low power consumption also makes them useful for some medical applications. For example, a thin-film plastic sensor can be attached to the skin and used for real-time monitoring of the arterial pulse.

36. Advantages and disadvantages One of the main advantages of piezoelectric pressure sensors is their ruggedness. This makes them suitable for use in a variety of harsh environments. Apart from the associated electronics, piezoelectric sensors can be used at high temperatures. Some materials will work at up to 1,000ºC. Piezoelectric sensors can be easily made using inexpensive materials  The output signal is generated by the piezoelectric element itself, so they are inherently low-power devices. If we use the high temperature, it may get affected.

37. Case study: THERMO FISHER SCIENTIFIC  is USA Based Bio-Technology and Healthcare Company. In early 2000s they recognized that they need better shock alarm system, The current old technology that was too slow.

38. Solution A piezoelectric crystal is placed between two metal plates which are normally in a perfect balance (even if they’re not symmetrically arranged) and does not conduct any electric current.  Mechanical stress or force are applied on the material by the metal plates, which forces the electric charges within the crystal out of balance. 

39. References   Holler, F. James; Skoog, Douglas A. & Crouch, Stanley R. (2007). Principles of Instrumental Analysis (6th ed.). Cengage Learning. p. 9.  ISBN   978-0-495-01201-6 . ^   Harper, Douglas.  "piezoelectric" .  Online Etymology Dictionary . ^   πιέζειν ,  ἤλεκτρον .  Liddell, Henry George ;  Scott, Robert ;  A Greek–English Lexicon at the  Perseus Project . ^  Jump up to: a   b   Manbachi , A. & Cobbold , R.S.C. (2011). "Development and Application of Piezoelectric Materials for Ultrasound Generation and Detection". Ultrasound.  19  (4): 187–96.  doi : 10.1258/ult.2011.011027 .  S2CID   56655834 . ^   Gautschi , G. (2002). Piezoelectric Sensorics: Force, Strain, Pressure, Acceleration and Acoustic Emission Sensors, Materials and Amplifiers. Springer.  doi : 10.1007/978-3-662-04732-3 .  ISBN   978-3-662-04732-3 . ^   Krautkrämer , J. & Krautkrämer , H. (1990). Ultrasonic Testing of Materials. Springer. pp. 119–149.  ISBN   978-3-662-10680-8 .