What is an Actuator and how do they work?

Part 1: What is an Actuator?

Experts project that the actuator and valve marketing will be worth more than $120 billion by 2024. For many, that's hard to comprehend, but actuators exist in more places than you think.

From automotive to machinery to home improvement, actuators are becoming more commonplace worldwide. This is most true in developing countries going through their industrial revolution.

To answer the question "What is an Actuator?", we look at some examples of actuators and how they work. Read on to learn more.

The actuation of machinery is the transfer of movement into energy. This occurs in various ways, such as using a motor, hydraulic cylinder, or an electric actuator.

These devices receive some external input and convert them into motion. They do so using stored energy in different stores.

Electric Actuators

Electric actuators receive power through an electric motor driving the device. The electric motor turns the electric actuator, which converts stored energy into motion. This process is reversible, meaning that the stored energy can be converted back into electricity and used to power a light bulb.

Benefits of Electric Actuators

Electric actuators are more flexible than their pneumatic or hydraulic counterparts and have many advantages. They can be used in extreme environments, over a wide temperature range, and with a wider voltage range.

They are also more durable than their more primitive counterparts. This is largely due to the motion control and positioning accuracy that they can offer.

They don't need high-pressure pumps or bulky air networks. Yet, this flexibility comes with a downside.

The size and weight of these devices are often larger than their counterparts. This makes them harder to install on-site.

Use Cases

These are most often used in a variety of industrial settings. One such example is the aerospace industry. In the aerospace industry, electric actuators are the primary means for controlling flight control surfaces.

Electric actuators using a coiled steel spring can also perform load holding applications. The use of an electric actuator in these applications is very common since the lack of moving parts makes them a reliable solution.

Electric actuators are also commonly used in synchronizing the three-phase electric motors that drive the rotors of a number of common helicopters. These electric motors are used to drive two or more rotors that are mechanically coupled to each other.

The work is divided equally among all the rotors with the electric actuators controlling each rotor's direction and speed. This allows for precise control of yaw, pitch, and roll.

Electric actuators are also used in the electronics industry, in particular laptops. They often also appear in commercial vehicles and other applications involving heavy-duty trucks. Electric actuators provide further convenience in medical equipment, telecommunications equipment, and automotive engines.

Pneumatic Actuators

These are a type of actuator that uses compressed gas to operate the pistons. They receive their energy from compressed gas sources, such as air and nitrogen. This power source is widely available and serviced compared to hydraulic systems.

Benefits of Pneumatic Actuators

Pneumatic actuators can perform a wide range of movement applications, from industrial to medical, and they are preferred because the mechanical parts are easy to replace. These are popular for their change and control capabilities.

Pneumatic actuators are also praised for their compact and lightweight designs. These provide more opportunities for installation throughout the workplace.

Use Cases

Pneumatic actuators are also popular in the medical industry. They help with ventilating or positioning patients. They are used to provide oxygen, remove carbon dioxide, and control the flow of air or liquid.

Pneumatic actuators are used in the pharmaceutical industry to provide high-volume airflow pressure into small compartments.

Pneumatic actuators have their uses in the food and beverage industry too. But they're also most often used in the automotive and transportation industries. Here, they control propeller blades and similar types of machinery.

Hybrid Actuators

A hybrid actuator is a combination of two or more actuators, usually mechanical and electric, to create motion. The mechanical actuator provides the movement while the electric actuator provides power. This creates more functionality and ensures that the device does not break down.

Benefits of Hybrid Actuators

Hybrid actuators are seen as cost-effective due to their flexibility. They are also easy to install and maintain since they do not require high-pressure pistons or motors. They are able to reach locations that pneumatic or hydraulic actuators cannot because of their ease of installation.

Pneumatics-Mechanism Actuators

Pneumatics-mechanism actuators are most common. They combine both the movements of pneumatic and electric actuators. Pneumatic, electric hybrid devices can make the most precise movements in various situations.

Industrial pneumatic hybrid systems can perform various functions, including positioning an object. The most common use for these devices is in the construction of a home or office.

But they can also help with measuring a distance or directing airflow a certain way. For instance, these systems are used to direct compressed air to a series of pipes, providing extra force to turn a valve after the pressure is increased.

The movements make use of pneumatics and motors. These movements allow for more flexibility in the movement of parts.

As a result, these types of hybrids create advantages unmatched by other actuators. This makes them ideal in medical applications or electrical applications.

Electro-Pneumatic Actuators

The electro-pneumatic hybrid actuator is one of the most common hybrid devices. The basic construction is a basic electro-pneumatic driven system that introduces pneumatic movement.

The first system is an electric motor driving to move the cross point. This is the point at which two components connect to drive movement.

The second system is a "wrist-type pneumatic valve" that drives the elbow joint. This pneumatic valve consists of an electro-pneumatic driven torque rod. It also has a pilot pneumatic cylinder movement.

The longitudinal movement of the torque rod causes rotation in the pilot cylinder. By its connection with the elbow joint, it can drive movement.

Hybrid pneumatic-mechanical actuators are common in metalworking applications. They're also aplenty in the automotive, medical, and aerospace industries.

Use Cases

Hybrid actuators can perform many tasks at one time for several different applications. One example of this is LED dimming and control (LEDs need current that varies based on brightness). Another example is oil level measurement (oil pipes need backpressure).

Hybrid actuators are also useful for detecting pressure flow. They are also used for temperature control in water or air heaters.

Hydraulic Actuators

Hydraulic actuators are very versatile and exist in a wide variety of applications. They are powered by hydraulic fluid that runs through a hydraulic system to its movement.

Hydraulic actuators work under pressure by a pressurized fluid. This fluid sits in an internal reservoir. This chamber prevents leakage when the actuator's output turns on.

The pressurized fluid travels to the actuator in two different ways. Hydraulic hoses create a closed circuit between the reservoir and the actuator.

Hydraulic valves bypass system power from the reservoir straight to the actuator. This results in the creation of an open-circuit system.

When air pumps into a hydraulic tube, it compresses and begins to heat up. The compressed air causes a space-heater effect. The temperature of the actuator rises a lot.

It does this by turning the valve off and on causes it to heat and cool at speed, riding a thermal loop. The result is a vibrating action that creates a sound.

Benefits of Hydraulic Actuators

Hydraulic actuators can make a wide range of movements. You can find them in many places for their adjust and control capabilities. They're also very durable and compact, requiring less maintenance than pneumatic and electric actuators.

Use Cases

Hydraulic actuators are capable of performing a wide range of movement applications. They're often used in very harsh environments with high levels of vibration. Hydraulic actuators work best in applications that need great force, like opening doors and cracking nuts and bolts.

Part 2: Types of Actuator Mechanisms

Aside from how the actuators get their power, there are other defining factors. For example, actuators categorize by how the actuators operate within their mechanisms. These different types generate different movements, depending on the intended use case.

Linear Actuators

Linear actuators are designed to move objects in a straight line. These types of actuators have one or more shafts that operate on linear friction.

Thus, linear actuators use linear motion to perform the movements needed to act. It is most often used for motion control applications. For example, they're popular as robotic arms and industrial applications in manufacturing.

Benefits of Linear Actuators

This mechanism is very simple, versatile, and reliable. Furthermore, it can be very robust when conditions are harsh, or the work environment is rough. It also allows for a large degree of control over the movement that occurs and works well when needing to move very heavy objects with extra force, as it's easier to apply force in one direction than multiple at once.

Use Cases

Linear actuators are often used in applications such as robotic arms. Here, a linear mechanism causes the movement. They're also used in automated car washing, car tire repair, and moving parts of machines. 

They're also great for DIY tasks. Check out our favorite DIY builds using linear actuators for some inventive ideas!

Rotary Actuators

A rotary actuator is a mechanism that moves an object in a circular or spiral motion. This type of mechanism works on the principles of a cam-and-groove mechanism. It consists of either a motor, gearbox and screw thread or a motor, gearbox and cam.

Benefits of Rotary Actuators

Their ability to create very precise movements makes them great for large-scale specialist projects. That said, they're complicated to design as different models often need different types of movement to achieve the same goal. This can create a bottleneck in the design process and delay production time.

Use Cases

Rotary actuators are often used in applications that need high levels of accuracy. For example, they're often used in medicine, such as patient beds, robots that aid surgeries, and other high-productivity medical equipment.

They're also used to control machines that move parts, such as a car's steering system or the combine harvester's rotating head. Semiconductors are also used in a variety of consumer products, such as toys and garage doors.

Solenoid Actuators

Solenoid actuators move objects in a linear or rotary motion using solenoids. They're based on either vacuum, current, or pneumatic mechanisms.

A solenoid is a cylindrical tube that has electromagnetic coils inside it. When an electric current passes through the coils, they become magnetized and produce a magnetic field inside the tube.

The applied force creates linear movement along the axis of the metal tube. Because of this, the solenoid becomes magnetized as well, depending on how many revolutions per minute it turns. The solenoids can also create rotary motion with a gearbox attached to them.

Benefits of Solenoid Actuators

Solenoids, unlike most other types of electrical actuators, are reliable and can create a range of motions. This is because they are made out of a material that’s efficient and can handle different voltages.

They don't use much power, so they're great for motion control applications that need small amounts of energy. Further, they don't take up much space, meaning you can create products with greater versatility.

These mechanisms are very precise in movement and efficiency, which means they can perform work at speed.

Use Cases

Solenoids are often used in domestic and industrial appliances, such as fans, motors, and heating elements. They're also used for many other applications, such as industrial robotics and vending machines. Many more applications utilize solenoids for their durability and reliability.

Diaphragm Actuator

A diaphragm actuator is a type of actuator that uses a flexible membrane to move an object. These actuators can create movements in a wide range of directions with very small amounts of force. As a result, they have many different applications.

Some examples include keeping doors closed and opening and closing fans and valves. They can also create sonic movement instruments.

A diaphragm actuator moves an object using the principles of a pneumatic cylinder. A pneumatic cylinder has a sealed chamber divided into compartments filled with compressed air or liquid. During the object's movement, the compartment changes shape and displaces air or liquid into the rest of the chamber.

The amount of change in shape that occurs in the chamber depends on the force applied to it. Because of this, the diaphragm actuator can create movements with very little force and move objects in a wide range of directions.

Benefits of a Diaphragm Actuator

The diaphragm actuator has many advantages. It's easy to get it set up and simple to program. It's also very versatile because it can control machines, doors, and many other potential applications.

Use Cases

In many applications, the diaphragm actuator cannot move objects in many directions because of its limited range of motion. There are also limitations with materials used in actuators.

These limitations are such as the applied force or the direction in which it can move. These limitations relate to the size and flexibility of the materials used.

Piezoelectric Actuators

A piezoelectric actuator is a special type of actuator that uses the principles of a crystal to create movements. Each piezoelectric material creates a force in response to an electric current passing through it. Because of this, the piezoelectric material becomes polarized and moves.

The piezoelectric actuator comprises a crystal with electrodes attached to it. When an electric field mixes with the crystal, it charges separately.

This creates a negative charge in the electrodes. The crystal is then attached to a base.

The separation and redistribution of charges create a magnetic field and cause the crystal to expand or contract. This creates linear movement along one axis. Piezoelectric materials have natural frequencies where they vibrate based on their physical properties.

Using different types of crystals and attaching electrodes makes it possible to create movements on a very small scale.

Benefits of Piezoelectric Actuators

Piezoelectric devices are great for creating precise movements. They don't take up much space so that you can fit them into a wide range of products.

They're also easy to manufacture. Thus, it's possible to get them set up and functional in your product faster than otherwise possible.

Piezoelectric actuators have a costly manufacturing process and are not as durable as other types of actuators. They're also restricted by levels of the natural frequencies used for moving.

Also, piezo are part of the same family as quartz crystals, fragile and break with ease. Because of this, specialists must maintain them with the utmost care and precision.

Use Cases

There are a wide variety of applications of piezoelectric actuators. They're used in a range of technologies, including consumer products, industrial and medical technology. They're found in:

A solenoid is a type of electromagnet. Solenoids work by having an iron core that's covered with insulating material.

When a current passes through the core, it creates a magnetic field and pulls on the surrounding material. They're used to create precise movements and create very small movements using low amounts of energy.

Magnetic Levitation Actuators

Magnetic levitation actuators use an electromagnet to move an object on a magnetic form. This creates a wide range of movements useful in industries such as robotics and machine automation.

The actuator makes use of two disks with electromagnets attached to them. The disks are then placed over one another, with the magnets facing one another. When current passes through the electromagnet, it pulls into the adjacent electromagnet.

When this happens, it produces an opposing force and causes the disks to move. If more current passes through the electromagnet, more of this opposing force occurs.

Benefits of Levitation Actuators

Magnetic levitation actuators are very reliable and simple to set up. They're also versatile because they can control machines. One example is an automated assembly line.

There are many applications where magnetic levitation occurs, such as automotive, manufacturing, and other process-driven industries.

There are some drawbacks to magnetic levitation actuators. Because of the complexity of the magnetic field and the system in which it moves, they can be vulnerable to any kind of error, like a sensor malfunction or other problems. They're also more expensive than other types of actuators because they're more complex to manufacture.

Use Cases

Maglev actuators have many applications. Some applications include lifting heavy objects, such as cars or trains. They're also used for controlling a large number of movements and for moving objects with precision

Part 3: Types of Actuator Applications

We've already highlighted some use cases above for actuators, but now let's delve deeper into the main industries and see how to use a combination of these different types of actuators.

Industrial Actuators and Automation Systems

Industrial actuators work well in manufacturing. They're used a lot in factories to improve process efficiency. They're very versatile actuators.

They work well for electrical, mechanical, and motion control applications. These actuators also automate assembly lines and other operations to increase worker productivity.

Consumer Electronics

Another example of an actuator in this space is the accelerometer used to control the device's movement.

Consumer electronics provide personal enjoyment. Yet, these products have become essential to everyday life because they've helped make our lives easier.

The first consumer devices that use actuators are televisions and remote controls. Nowadays, many other types of consumer electronics use actuators.

An actuator in consumer technology is the touchscreen, made to sense input from the user's touch on the screen and then move as appropriate. For example, smartphones and digital cameras both have actuators to help control movement and create more precise actions

Another example of an actuator in this space is the accelerometer used to control the device's movement. A variety of consumer products use piezoelectric actuators to create the movement needed for the proper usage of the device.

Automotive

Automotive actuators control the movements that occur in cars. They can also control other components inside a vehicle, like automated steering wheels and seat adjustments. There are also various types of actuators that are used in vehicles to control the movement of wheels.

One kind of automotive actuator is a pneumatic cylinder. It's attached to a piston, which then pushes out air under pressure. This produces a powerful push that causes an object to move quickly or stop moving altogether.

Another type is a chain drive, which consists of multiple gears and rollers. With this type of actuator, the gears and rollers change the movement of the car into a circular motion. There are other types of automotive actuators that work in a similar way.

Medical Technology

Medical technology exists in hospitals that put in place mechanical gantries to move the equipment around and control motion with remote controls. For example, a gantry system can be used to move an MRI machine with the push of a button

In the medical industry, actuators are used to control mechanical systems like surgical tools or manipulators. This makes it possible for surgeons to perform more precise motions. Medical devices also use electronic actuators to perform tasks like opening and closing valves.

Semiconductors and Sensors

Semiconductors are used in many types of equipment, including medical technology, energy management, military systems, industrial products, and personal computers. These products rely on sensors to gather information regarding the operation of a machine and then send it back to an actuator. An AC drive uses semiconductors as a sensor to measure the frequency of electricity.

The circuits received then transmit data to the driver's panel, which changes the speed and direction of the motor that moves the electric motor in order to adjust its temperature. Also, they're often used in commercial products, like the hard drives and memory modules included in computers and other electronics that we use every day.

Robotics

Robotics as a field of science translates into many wider applications. These include medicine, manufacturing, security, space exploration for research, military and recreational uses.

Actuators in robotics help to control movement and create precise actions. Some robotic applications include medical technology, such as surgery robots, to perform delicate operations inside the body.

Military

Military applications for hybrid actuators include positioning or rotating weapons using electric motors to rotate turrets and missiles. Positioning a weapon requires precision unlike the use of pneumatic or hydraulic hybrid actuators.

They can be guided by sensors such as lasers, infrared radiation, radar imaging, and more. They can also be guided in the vertical direction by magnetic forces or wires.

Construction

A wide range of construction equipment uses actuators. Construction equipment includes a variety of tools that help make building and construction faster and more efficient.

Construction equipment can also perform various tasks, such as excavating, grading, piling, driving, lifting, and moving materials. Actuators work with all these machines to create an efficient workflow.

Agriculture

There are many applications for actuators in agriculture, including using robotic equipment, such as tractors and sensors to watch crop conditions. These applications help farmers to manage their farms better and increase the quality of crops.

As well as using actuators, agricultural machinery often uses mechanical controls to control the work. These controls help contractors or farmers to make adjustments during the labor process.

Food Processing

You can find actuators in food processing equipment, such as blenders, presses, slicers, and graters. These actuators help control the different processes in food processing using servos and help create a safe, sanitary environment in food production.

Electronics Manufacturing

Electronics manufacturing uses many types of actuators that create precise actions needed in assembly lines. Some applications include using robotic arms to mount circuit boards and other electronic components.

In addition, actuators are used for functions like heating plastic during the manufacturing process and other functions that require precise movements.

Surveying and Geology

Actuators are used in geology to create very precise movements, such as drilling or using a magnetometer to detect the changes that occur in the magnetic field. They're also used to create precise movements for various other applications.

Civil Infrastructure

Many applications for actuators in civil infrastructure include taking public transportation, dam construction, and earthquake bracing. Besides, they're used to control the movements of bridges and underground highways.

Construction

A wide range of construction equipment uses actuators. These products help make building and construction faster and easier. A variety of tools are also used to perform various tasks, like driving, excavating, grading, pushing, or pulling materials.

Part 4: How to Choose the Best Actuator

Now you've got all this information available, what next? Well, there are a few factors to consider, and we've listed them below:

Power Consumption

When choosing a type of actuator, you should calculate power consumption. This will help you determine if the motor is powerful enough to operate at its full potential.

Using a linear or rotary mechanism, you should consider the weight, speed, and power consumption. It would be best to consider any other alternative solutions for precise control to better meet your needs.

Use Case

When choosing a type of actuator, you should also use the product's performance criteria to assess its performance. For example, you should compare the specifications of the actuators.

Also, you should compare their strengths and weaknesses as addressed above, as well as your intended use case.

Cost

In general, solenoid actuators are more expensive than linear or rotary mechanisms. This is because they need more time and money to design and produce. Yet, this isn't always the case with consumer products that use them for motion control applications.

When choosing an actuator, you should also consider the cost of ownership. You should compare the life span of a product with that of other products. This can help you determine which product will be cheaper in the long run.

It's also important to compare the costs of maintenance and operation. As well as this, you should also take note of any dangers and hazards associated with a specific type. By understanding these factors, you can make an informed decision.

If in the future you are in need to replace your linear actuator, our replacement actuator article will be of great help.

If you know what specifications you need your actuator to be, but are unsure what exact actuator you need, or are just wanting to know which actuators FIRGELLI sell, which are perfect for your application? Then our Actuator Widget will provide you with those answers.

Actuators Are More Popular Than You Know

We've explored different types of actuators and looked at the most common applications. It's now time to come together and make useful products.

For example, linear actuators control robots' movements in factories. Pneumatic actuators help lift heavy objects.

The benefits of using actuators are many. They make it much more convenient to perform tasks that need precision or a wide range of motions. But in most cases, they're easier to control than other mechanical components.

So now you're a pro in the know with actuators, it's time to shop online at our store. Contact us today and we'll help you find the actuators that will leverage your project to its full potential!