Piezo Actuators

What Are Piezo Actuators?

The purpose of an actuator is to convert electrical energy into mechanical energy. Piezoelectric actuators utilize the inverse piezoelectric effect to generate physical displacement in response to an electrical input. Piezo actuators are used for their precise control and efficiency in a wide variety of applications, with precision down to the micrometer. There are multiple types of actuators that suit different needs based on their unique properties.

Piezoelectric actuators are very simple in design with little to no maintenance or lubrication required. There are virtually no moving parts and they are quite reliable. For these reasons, they are best suited for applications requiring precise movement, for example in motors and a growing variety of other practical uses. Piezo actuators are widely utilized across many industries, including medical, industrial, commercial, machinery, automotive, and aerospace.

What Are Examples Of A Piezo Actuator?

One example of a piezoelectric actuator is the piezo stack actuator. This type of actuator consists of multiple layers of piezoelectric material stacked together and sandwiched between electrodes. When a voltage is applied to the electrodes, the piezoelectric layers expand or contract, causing the actuator to move. The movement can be in the form of linear motion, rotary motion, or even flexural motion, depending on the design and configuration of the actuator. Piezo stack actuators are known for their high precision, fast response times, and high force output, making them suitable for applications such as nanopositioning, precision machining, valve control, and active vibration damping. Their compact size and ability to operate in harsh environments also contribute to their popularity in various industries and research fields.

Piezo Strip
There are multiple types of piezo actuators, including multilayer piezo stack actuators, piezo strips, piezoelectric disc actuators, piezo tube actuators.

Piezo Actuator Manufacturer

Piezo Direct is a leading manufacturer of piezo actuators, specializing in the production of high-quality and reliable piezoelectric devices. The manufacturing process at Piezo Direct involves state-of-the-art technologies and stringent quality control measures.

The production of piezo actuators begins with the selection of premium-grade piezoelectric materials, such as lead zirconate titanate (PZT), known for its exceptional performance and durability. These materials are carefully sourced to ensure consistent and reliable actuator performance.

Piezo Direct utilizes advanced fabrication techniques to shape the piezoelectric materials into the desired actuator designs. This involves precise cutting, dicing, and shaping processes to create the necessary geometries and dimensions. The company employs specialized machinery and equipment to achieve high precision and accuracy during these manufacturing steps.

The next stage involves the assembly and bonding of the piezoelectric elements to create the complete piezo actuator. Piezo Direct employs advanced bonding techniques, ensuring a strong and reliable bond between the piezoelectric layers and electrodes. This guarantees optimal electrical contact and efficient transfer of electrical energy into mechanical motion.

To ensure consistent quality, each piezo actuator undergoes thorough testing and characterization. Piezo Direct employs rigorous testing protocols, including electrical testing, mechanical testing, and environmental testing, to assess the performance, reliability, and durability of the actuators. Only actuators that meet stringent quality standards are approved for further processing and shipment.

Piezo Direct also places a strong emphasis on customization and customer requirements. The company works closely with clients to understand their specific application needs and provides tailored solutions accordingly. This may involve customization of actuator dimensions, electrical characteristics, and mounting options to ensure seamless integration into the customer’s systems.

With their commitment to quality, precision manufacturing processes, and customer-centric approach, Piezo Direct has established itself as a trusted and reliable provider of piezo actuators. Their expertise and dedication contribute to the development of cutting-edge technologies and advancements in various industries that rely on piezo actuation.

Please give us an opportunity to show you what we can do. The entire process is fast and efficient. Call us today, in California, at 650-375-7003.

Detailed Mechanics

Detailed Mechanics of Piezo Actuators

The inverse piezoelectric effect occurs when an electrical charge generates mechanical energy. When an electrical voltage is applied to a piezoelectric actuator, the piezo actuator will deform and generate some kind of precisely controlled physical displacement. The resulting displacement can be used to activate switches or alarms, create sound, release fluid, auto-break or auto-focus, and much more. Low stroke or high stroke can be achieved depending on the shape and construction of the piezo actuator. The higher the mechanical stress on the piezo actuator, the high voltage produced. If one end of the piezo actuator is fixed, the other end bends to cause deflection. If both ends of the piezo actuator are fixed, the center deforms the most to generate displacement.
piezo tube actuators
Piezo actuators are able to generate physical displacement as a result of an applied voltage.
Piezoelectric actuators can either be constructed as a stack, bimorph, or unimorph, depending on the application and desired results. Stack piezo actuators generate low stroke, high blocking force, and high load capabilities making them extremely suitable for high precision applications given their ability to produce linear movement in small and precise amounts. Stack piezoelectric actuators can be made as either discrete stacks, where the components are fired separately and connected later via adhesive, or monolithic stacks where they are co-fired and bound by subjecting them to intense heat and pressure, or sintering. Bimorph and unimorph piezo actuators are constructed with layers of active piezoelectric material that bend and contract when a voltage is applied. Bimorph piezo actuators have two active piezo layers and unimorph piezo actuators have one active piezo layer often attached to a passive substrate layer. The electrical current causes one layer to contract and the other to expand, creating a bending motion. The resulting deflection generates more stroke and less blocking force than stack piezo actuators.

Advantages and Disadvantages

Piezo actuators are extremely reliable and versatile. They are small, flexible, can be manufactured into any shape, and have no moving parts that require lubrication. Piezo actuators have very low energy consumption, high force generation and load capabilities, and can operate in vacuum and cryogenic environments. They have very fast response times and can be made to operate at high voltages. Piezo actuators may need to be mechanically preloaded or amplified if used as a driver depending on the application.

Advantages of Piezo Actuators:

  1. Precise Movement: Piezo actuators offer exceptional precision in movement, allowing for accurate positioning and control. They can achieve sub-micrometer and even nanometer-level displacements, making them ideal for applications that require high precision, such as microscopy, nanomanipulation, and optics.
  2. Fast Response Time: Piezo actuators have an incredibly fast response time, often in the microsecond range. They can rapidly change their shape and position, enabling them to quickly adapt to dynamic requirements and perform high-speed operations. This attribute is advantageous in applications like active vibration control, scanning systems, and fast switching devices.
  3. High Force Output: Despite their small size, piezo actuators can generate significant force output. They can exert forces ranging from a few newtons to hundreds of newtons, depending on the design and configuration. This characteristic makes them suitable for applications that require both precision and high force, such as precision machining, valve control, and robotics.
  4. Wide Frequency Range: Piezo actuators exhibit a wide frequency range, allowing for precise control across different frequency bands. They can operate from DC (direct current) to several kilohertz or even megahertz frequencies. This versatility makes them valuable in applications such as ultrasonic cleaning, ultrasonic machining, and high-frequency sonar systems.
  5. Compact and Lightweight: Piezo actuators are compact and lightweight, making them easy to integrate into various systems and devices. Their small size and high power density contribute to space-saving designs and enable the development of portable and miniaturized devices. This advantage is particularly relevant in fields like aerospace, medical devices, and consumer electronics.


Disadvantages of Piezo Actuators:

  1. Limited Stroke Length: Piezo actuators typically have a limited stroke length compared to other actuation technologies. While they excel in achieving small displacements, they may not be suitable for applications that require long linear or angular movements. External mechanisms or hybrid actuation systems may be needed to overcome this limitation.
  2. Voltage Requirements: Piezo actuators require high voltages for operation. The voltage required to drive a piezo actuator can range from tens to hundreds of volts, depending on the specific actuator and application. This high voltage demand necessitates appropriate power supplies and voltage amplifiers, which can add complexity and cost to the system.
  3. Temperature Sensitivity: Piezo actuators can be sensitive to temperature changes. Extreme temperature variations can affect their performance and cause variations in their characteristics, such as displacement and resonant frequency. Temperature compensation techniques or environmental control may be necessary to mitigate these effects.
  4. Hysteresis: Piezo actuators may exhibit hysteresis, meaning that the output motion may not precisely correspond to the input voltage or control signal. This non-linear behavior can introduce errors and require additional compensation techniques for achieving accurate positioning.
  5. Fragility: Piezo actuators are relatively fragile compared to other actuation technologies. They are susceptible to mechanical stress and can be damaged if subjected to excessive loads or impacts. Proper handling and protective measures are crucial to ensure their longevity and reliability.

While piezo actuators offer numerous advantages, it is important to consider these disadvantages and evaluate their impact on the specific application requirements before incorporating them into a system.

Piezo stack actuators can be custom manufactured in various shapes and sizes according to the intended application.
Piezo actuators can be custom manufactured in various shapes and sizes according to the intended application.

Applications

  • Sound generation and amplification
  • Musical pickups
  • Household commercial items
  • Alarms (microwaves, clocks, etc.)
  • 3D and inkjet printers
  • Fine machinery
  • Fuel injectors
  • Valve and pump control
  • Ultrasound equipment
  • Microdosing and nanodosing
Piezo actuators are widely used for precision movement across many industries.
Piezo actuators are widely used for precision movement across many industries.

Applications of Piezo Actuators

Piezo actuators are a valuable and versatile element with limitless capabilities across all industries, such as commercial, industrial, automotive, aviation, aerospace, and electronic. In common household items, piezo actuators are responsible for igniting lighters, sounding alarms, and amplifying sound in speakers and microphones. Coupling the displacement’s power with rapid vibration makes for a clear sound with potent sound pressure. Sound-generating buzzers, alarms, and buttons implement piezo actuators to bend or deform at a signal and create a sound. This can be seen in timers, clocks, microwaves, car keys, PIN pads, and alarms and buzzers. Larger machinery such as 3D printers, inkjet printers, Braille machines, and weaving machines all utilize piezo actuators for fine movement and precise adjustments. In printers, piezo actuators are used to control the dispensing nozzle, releasing the precise amount of ink needed to create the print received through an electrical signal.

In the automotive industry, piezo actuators are found in fuel injectors, valve and pump control, and other auto functions, such as automatic breaking. Piezo actuators respond to electrical signals in the car’s computer and make mechanical and physical adjustments within the vehicle instantly.

Piezoceramic actuators are also excellent for high precision nano movement and dosing. In medical applications, piezoelectric tube actuators are employed in microdosing machines and ultrasound equipment. In some minimally invasive procedures, piezo actuators are implemented into catheters generate ultrasound waves, which increase the permeability of the blood vessel walls and make it easier for medication to penetrate.

Piezo actuators are a valuable and versatile element with limitless capabilities across all industries, such as commercial, industrial, automotive, aviation, aerospace, and electronic.

Shapes

Multilayer Stack Piezo Actuators

Multilayer stack piezo actuators consist of stacks of piezo elements that expand when an electrical charge is applied. Longitudinal and shear displacement can be achieved with stack piezoelectric actuators. Multilayer stacks are commonly utilized for precision machinery and control in industrial, medical, aerospace, and automotive industries. Learn more about piezo multilayer actuators here.

Disc Piezo Actuators

Piezoelectric actuators in a disc shape are circular piezo elements often found in automotive functions, sound production and amplification, liquid and fluid level measurement, and ultrasonic applications. As piezo actuators, discs are utilized in the automotive, industrial, commercial, and ultrasonic applications to detect changes and perform adjustments. Learn more about piezo disc actuators here.

Strip Piezo Actuators

Piezoelectric actuators in a strip shape are thin pieces of active piezoelectric material connected to a passive layer. Piezo strip bending actuators have either one active piezoelectric layer or two active piezoelectric layers that bend to create deflection. Strip piezo actuators are commonly utilized in valve and pump controls, accelerometers, sound production, touch switches/controls, and fine machinery. Learn more about strip piezo actuators here.

Ring Piezo Actuators

Piezoelectric actuators in a ring shape are often used in multilayer stack piezo actuators to produce linear movement. Ring piezo actuators are often found in ultrasonic applications, nanopositioning, microscopy, and precision machining. Learn more about piezo ring actuators here.

Tube Piezo Actuators

Piezoelectric actuators in a tube shape are also known as piezoelectric cylinders. Tube piezo actuators can generate axial displacement (changes in length) or radial displacement (changes in diameters). Tube piezoelectric actuators are often utilized for flow and level measurements and adjustments, scanning microscopy, and microdosing, commonly found in the industrial and commercial industries. Learn more about piezo tube transducers here.

Bimorph Piezo Actuators

Bimorph piezoelectric actuators consist of two active piezoelectric layers bonded to a passive metal substrate or bonded directly together. One piezoelectric layer contracts while the other piezoelectric layer expands when a mechanical or electrical input is received. This causes a bending motion that can either perform a desired task or generate a readable electrical output. Learn more about piezo bimorph transducers here.

Unimorph Piezo Actuators

Unimorph piezoelectric actuators consist of one active piezoelectric layer often bonded to a passive metal substrate. Unimorph actuators deform in a single direction when activated by an electrical input and translate it into a mechanical output.

Plate and Block Piezo Actuators

Piezoelectric actuators shaped as plates and blocks can be engineered into any shape. Plate piezo actuators are commonly used in multilayer stack actuators and block piezo actuators are often used in ultrasonic applications. A DC voltage will cause piezo plate actuators to deform while an AC voltage will cause it to vibrate. Piezo block actuators are used for high power generation and applications. Learn more about plate and block piezo actuators here.