Piezo Stack

Your Best Piezo Stack Manufacturer

PD ceramic offers piezo stack in different shapes and dimensions. Because of this, our piezo stack has been applied in a large variety of domains like Optronics, military, aerospace science and technology, MEDTEC, precision metrology, etc. At the current stage, our piezo stack is applied on piezo stack linear stages. Based on that, it can realize a dynamic process such as high-frequency error compensation, tracking, fast stepping, or continuous scanning, etc. Some of our customers have good feedback about it. The piezo stack is ultra-compact in size and very low in power consumption. It is widely applied to consumer electronics like a smartphone speaker, etc. In order to meet the varying requirements from customers in different demanding applications, PD ceramic has developed different piezo stacks. As a premier piezo stack supplier in the market, our piezo stack engineer will help you solve your toughest engineering challenges. Our piezo stack will help you minimize the production cycle times and maximize your outputs. We would be happy to take part in your engineering automation and give our 24/7 technique support.

Piezo Stack: The Ultimate Guide by Method and Principle

Are you looking for a piezo stack? Do you know how it functions, the designing process and the mode of selection? Today’s guide will take you through all the very facts that you need to know about a piezo stack. It includes the benefits, different types, and applications among other important features. Let us embark on this journey and find out more about this device.

Chapter 1: What is a Piezo Stack?

Let us begin with the basics and divide the name into two parts i.e. piezo and stack. The word piezo originates from a Greek word which simply means pressure. A piezo element is a type of ceramic that can contract and expand resulting in the production of electric charges. Any form of deformation on the piezo will lead to the generation of electric charges. Figure 1 Piezo element – Photo courtesy: Electronic Design A stack, on the other hand, is a pile of any substance where one substance is on top of the other. Implying, multiple piezo elements on top of each other will form a piezo stack. Figure 2 Piezo stack – Photo courtesy: PHYSIK INSTRUMENTE Stacking up or piling the piezo elements produces a combination effect from each piezo element. What do I mean? One piezo element produces an electric charge or force that can initiate a movement. To get a greater force or more electric charges, you will have to put more piezo elements together. Multiple piezo elements on top of each other produce enough electric charge to create the movement that you desire. As we proceed, you are going to learn more about the benefits of the piezo stack in the next section.

Chapter 2: What are the Advantages of Piezo Stack?

Stacking up multiple piezo elements not only produces more force but has a series of benefits. Among the benefits of the piezo stack are: Figure 3 Piezo stack

·  Fast Response

A piezo stack can produce electricity very fast as soon as they deform. The rapid response makes it a very powerful element for initiating rapid action. Whenever you need to produce electric currents faster, you can use the piezo stack.

·   High Acceleration Rates

The speed at which the piezo stack can generate electricity is very high. As soon as it generates electric power, the rate of acceleration is amazing. You can complete any task using this kind of force as soon as you begin using it.

·  High Power Generation

The power that a piezo stack can generate is very high. You can use the power a piezo stack generates to power a lot of high power devices. It can also cause enough force that can cause movement.

· Compact Design

The piezo stack has a compact design that you cannot alter easily. The compact design improves its stability making it a device that you can rely on. It also minimizes the space that a y other forms of design would occupy.

· High Mechanical Power Density

The magnitude of mechanical power that the piezo stack can produce is very huge. The density of mechanical power in store in a stack of piezo elements can produce a lot of force and last longer. This attribute increases the durability of the piezo stack.

· Low Power Consumption

To produce the electric charge, you desire, you have to pass enough power through the piezo stack. A piezo stack will need very little power to generate even a greater force. You will be spending very little energy to produce very huge results. Let’s have a look at some of the activities of the piezo stack.

Chapter 3: What are the functions of Piezo Stack?

A piezo stack has quite a number of functions. Some of the functions include:

i. Displacement

A single piezo element in a stack has alternating polarities. On the same note, the electrical field is often in a parallel direction to the polarization. Figure 4 Displacement in piezo electric – Photo courtesy: PIEZO TECHNOLOGY When you apply a voltage to the piezo element, it will produce a displacement or a strain. The strain or displacement that it induces is often in the direction of polarization. The movement of the piezo element is equal to the quantity of voltage that you will apply times piezoelectric coefficient. Since there is more than one piezo element, the resultant force is huge and can cause a displacement.

ii. Voltage and Electric Field

The piezo stack can either be low voltage or high voltage. I am referring to the maximum voltage that you can use to produce maximum results. You can know the amount of voltage to apply by looking at the type and thickness of the piezo material. Figure 5 Electric field To get a higher electrical field, you have to decrease the thickness of the layers. On the same note, for any electrical field, when you decrease the layer thickness, the driving voltage will also decrease. Understanding this principle will help you in applying different parameters as you use the piezo stack.

iii. Force and Stiffness

The generation of force by a piezo stack depends on the stiffness of the piezo stack. You can determine the stiffness of the piezo stack by looking at the elasticity of the piezoceramic material. Figure 6 Force and stiffness in piezo element – Photo courtesy: PIEZO TECHNOLOGY Despite the small size of the piezo stack, it can produce great forces ranging to tens of thousands of newtons. In the stiff state, the piezo stack does not need any power as no operations are going on. On the same note, the piezo stack will remain in the stiff state without generating heat. You can, therefore, have a sense of security that your device is safe. Is it becoming more interesting? Well, you are yet to learn more about the piezo stack. Let us proceed and look at the different types of piezo stacks available.

Chapter 4: What are the Common Types of Piezo Stack Actuators?

In your search for different types of piezo actuators, you will come across three main types which are: Figure 7 Piezo actuator

1. Multilayer Piezo Stack Actuator

This is a type of piezo stack with more than one layer. Do not confuse a piezo stack with a multilayer piezo stack.  A piezo stack has multiple layers of piezo elements while a multilayer piezo stack has multiple layers of piezo stacks. Using the multilayer piezo stack usually comes with its benefits which include:

1. It allows for the higher operating temperature of up to 200 degrees centigrade. This allowance can vary depending on the type of multilayer piezo stack and the number of layers.
2. It features special electrodes that allow for more current reaching 20A.

• It features variable geometry depending on the design that you want. You may decide to have the inner hole assume a rectangular or round shape.

1. In many of the versions, you will find a multilayer piezo stack with a metal or ceramic tip.
2. You can also request to have an SGS sensor that will improve positional stability.

You can use the multilayer piezo stack in the following areas:

1. Industry and research
2. The cryogenic environment where there is a reduction in displacement.

• Precision positioning

1. High-speed switching
2. Adaptive and active systems

2. High Voltage Piezo Stack

High voltage piezo stacks allow you to use a higher voltage than usual. You can use it in different applications that usually require very high voltages. It features very strong materials that can withstand the high voltage. Since it allows high voltage current, it also produces a lot of heat. The materials are always strong enough to withstand the amount of heat that the device produces. In this case, you can either have a single layer or multilayer piezo stacks that can withstand the high voltage. Multilayer piezo stacks use a special and high-quality adhesive to bond the layers together. Since it operates under extreme temperatures, the device often features a casing. The casing can assist in stabilizing the piezo stack and also in the dissipation of excess heat buildup.

3. Low Voltage Piezo Stack Actuators

Low voltage piezo stacks can operate well in very low voltages. It takes the slightest application of low voltage to trigger the low voltage piezo stack to function. Why? The low voltage piezo stack consists of very thin ceramic layers. The small size allows it to react in a shorter period thus generating the force that you need. When operating a low voltage piezo stack, you will not expect it to generate a lot of heat. Despite the low voltage passing through the device, it is proper to have an insulator. The insulator will prevent you from any shock from the device. You can use it in different applications that do not depend on high voltages and excessive force to operate. With this in mind, let us look at how a piezo stack actually works.

Chapter 5: What is the Working Principle of Piezo Stack?

How does a piezo stack work? To answer this question, there are certain factors that you need to understand. The operating principle of a piezo stack depends on the type of piezo stack you are using. The difference in working principle may be in the level of voltage application or the number of layers. In this section, you are going to learn about the general working principles of a piezo stack.

Think of what happens when you switch on the electric current to pass through the piezo actuator. From the previous section, you know that when an electric current passes through a piezo element, it deforms. The piezo element can either expand or contract depending on the type. As the piezo stack element deforms, it produces a force that you can use to initiate movement. You have to place the piezo stack in a stable position to avoid movement when you apply the electric current. The ceramic material allows the piezo stack to control the heat it produces while it is working. You can also protect it with a metal casing to protect it from moving around and mechanical damage. The mechanical displacement or stroke of the piezo stack depends on the number of layers the design or model has. The more the number of layers a piezo stack has, the higher the mechanical displacement or stroke. The blocking force of the piezo stack is directly proportional to the cross-sectional area of the piezo stack. The wider the cross-sectional area the higher the blocking force of the piezo stack. In other words, any amount of pressure that can deform a piezo element is strong enough to create a piezo effect.

For example, when you apply enough pressure on the piezo stack in a lighter. It is capable of producing an electric current that can induce sparks and make a flame. You should be very cautious when you are operating these devices. Since it has an electric current passing through, there might be incidences of shock. The piezo stack usually has an insulator to protect you but you also have to be very careful. In case you need a custom piezo stack, you can come up with your own design. In the next section, we are going to take you through the designing process of a piezo stack. Let’s find out.

Chapter 6: What is the Piezo Stack Step-by-step Designing Process?

A piezo stack can take any form. This gives you the allowance to come up with your own design of a piezo stack. You must, however, consider certain factors when you are designing a piezo stack. These are the factors that will determine the functionality of the piezo stack. First, in your design, you have to consider the mechanical requirements for the piezo operations. The mechanical considerations include: Figure 8Piezo stack design

1. Mechanical stiffness
2. The length and cross-sectional area of the active material

• Load capacity you intend to apply and the force that you intend to generate. A piezo element can withstand different load capacities and generate a force proportional to the load capacity.

The maximum amount of force that a piezo element can produce will depend on these factors. Apart from that, your design has to include a casing that will protect the piezo elements. Since the piezo elements are brittle, you have to protect it from other devices that may cause mechanical damage. Secondly, you should look at the power requirements. You can either decide to have a piezo stack that uses high or low voltages. The higher the voltage the higher the capacitance and the wider the cross-sectional surface area. For example, in case you are designing a low voltage, medium load, multilayer piezo stack. You will need to specify the low voltage that you require. In this case, you can use a voltage of about 5 watts. Third, your design has to fit the application you intend to use it on. Since you can use the piezo stack in different applications, you have to know where you will be using yours. Is it a safe place with minimal interruptions or does it have other falling debris that might damage the device? This consideration will allow you to design a metal protector to cover the device from mechanical damage. Apart from the environment, the piezo stack usually works in conjunction with other devices. Your design should be able to fit properly with the other devices. Figure 9 Piezo stack design In other words, “Where will you position your piezo stack?” There is a constant need for accuracy and speed when you are designing a piezo stack. When designing your piezo stack, you need to be in close contact with your manufacturer. The manufacturer will assist you in aligning some of the factors that will determine the functionality of the device. With the approval from the manufacturer that the device can actually work, you can proceed to manufacture. In case you don’t have the time to come up with your own custom design. You can go for one that is already in the market. The next section takes you through all the aspects to consider when you are selecting a piezo stack.

Chapter 7: How to Select a Piezo Stack?

The other daunting task that you need to know about is the selection of a piezo stack. There are different types of piezo stacks available in the market from different manufacturers. To get a good piezo stack, you need to look at the following considerations. Figure 10 Piezoelectric stack actuator

· Capacitance

In simple terms, capacitance is the ability of a particular system to store electric charges. You can also describe it as a ratio of change in electric charges to the change in electric potential. No matter the explanation, capacitance of the piezo stack is a factor you have to consider. Why? Different piezo stacks, come with different rates of capacitance. Whenever you are purchasing a piezo stack, consider the one with greater capacitance. It improves the reliability of the device you are looking for.

· Thermal

Operating a piezo stack, usually produces a particular quantity of heat. The heat a piezo stack produces ma cause damage to the device if you don’t remove it. Instead of focusing on the dissipation of heat, why don’t you look for a device that generates less heat? Different manufacturers use different materials to make the piezo stack. A good piezo stack should not be producing excess heat. In case it does, it must have an inbuilt system that will dissipate excess heat.

· Electric Current Requirements

Your choice for electric current requirements depends on the application. Your application might require you to use high or low electric currents. Manufacturers, on the other hand, produce different types of piezo stacks that can work with different electric current requirements. You should, therefore, go for the piezo stack that will fit your electric requirements.

· Connecting Wires

When you are looking for a piezo stack, you should go for the one with the wires in place. You will save a lot of money and time by considering this type of piezo stack. There are also different options for wiring in a piezo stack. When you are selecting wire for connection, look at the following considerations:

1. Operation voltage
2. The intensity of the current you will be using

• The operating temperature of your application

1. The operating environment, for instance, a vacuum.

You should go for wires with PTFE insulation as they can withstand very high temperatures above 200 degrees. In vacuums, you will use wires with PTFE isolation to guarantee proper performance. Apart from that, you should also look at the thickness of the wire (AWG). You will select the wire thickness by looking at the current passing through the wire.

· Vacuum Compatibility

The piezo stack has to be compatible with the environment. You might decide to use the piezo stack in a vacuum. The specifications of a piezo stack in a vacuum are different from those of other environments. For example, in a vacuum, you need PTFE isolated wires for your piezo stack. You should also go for a device with lead-free solders and use copper, silver or tin for soldering. In other words, the piezo stack has to be compatible with:

1. Low pressure
2. Low outgassing and extreme cleanliness

• High temperatures

· Dimensions

In this case, the dimensions of the piezo stack will depend on the design you want. The bigger the dimensions, the greater the force that the piezo stack can produce. In that case, look at your application. Does it require a lot of force or a bigger piezo stack? With that in mind, you can decide on the dimensions of your piezo stack.

Chapter 8: What are the Common Applications of the Piezo Stack?

We are getting closer to making you a piezo stack expert. Before that, why don’t we take you through some of the applications of the piezo stack? Let us have a look at how the piezo stack works in the following applications.

· Piezo Feeder

The driving source of the piezo feeder depends on the piezo effect of the piezo stack. The piezo stack produces a piezo effect that produces enough force to generate a vibration. The vibration will, therefore, will drive the small parts of the feeder. In the long run, you will see a series of component transfers on the feeder.

· Piezo Electric Pump

The piezoelectric pump enables the pumping and delivery of fluids. The pump depends on the piezo effect to create enough force to push the fluid continuously. The small amount of power that passes through the piezo element produces enough force to pump fluids to greater heights.

· Piezo Print Head

Most of the printers in the market today have a print head with a piezo stack. The piezo stack provides the print head with the energy that it desires to make the prints. It is a technology that will save you a lot of energy in printing. The speed at which it produces the power reflects on the speed of the printing head.

· Fiber Modulation for Communication

Fiber modulation is a mode of transmitting information to different places. It works by sending light pulses through optical fibers. The electromagnetic carrier carries the information from the sender to the receiver. The piezo stack provides the electromagnetic carrier with enough energy to send the light pulses as a mode of communication.

· Proportioning Valves

This is a type of valve that relies on statics to initiate a reduction in pressure in an output line. This kind of action requires force to make it work. In most proportioning valves, the source of power originated from the piezo stack. It a component in a car that reduces the pressure on the brake fluid.

· Electrical Switches

An electrical switch depends on the piezo effect to generate a charge that turns on an integrated semiconductor. The semiconductor can be a field effect transistor that activates the output assemblies of the switch. In other words, it switches on the lights or the machine.

· Micro Pumps

The piezo element plays a huge role in micropumps for pumping and metering purposes. Due to the small volumes in one pumping cycle, you need enough energy to achieve higher flow rates. The micropumps have pump diaphragms, valve units working together with piezo stack to create the pump drive.

· Ink Jet Printers

This type of printer depends on inkjet technology and the drop-on-demand process for printing. The printer depends on the piezo stack effect to initiate a print. It has piezo stacks or crystals behind the print nozzle. Subjecting the piezo stack to an electric voltage initiates enough power for ink jet printing.

· Anti-vibration Devices

When you apply voltage to a speaker or a buzzer, it usually creates sound waves. When you apply the audio voltage signal to a piezoceramic, the material will vibrate the air. The piezo drivers, therefore, convert the low voltage from the batteries to higher voltages. This effect causes the piezoceramic to produce a vibration effect in the air and not the device.

Conclusion

Well, we have come to the end of the guide. I believe that this information will guide you in becoming a piezo stack expert. It will also set the stage for you to understand the different elements available in the piezo element industry. Lose your fears and complete your search for a good piezo stack. Have enough confidence because this time you have all the information at hand.