Pneumatic & hydraulic systems control and convert energy into mechanical action by manipulating pressurized gases or fluids, respectively. Each system operates under distinct principles that suit various industrial applications, optimizing tasks with specific power and precision requirements.

Pneumatic vs Hydraulic Power Systems: Working Principles, Differences, and Selection Criteria

<p dir="ltr" id="isPasted">Pneumatic and electrical actuators&nbsp;<a title="Pros And Cons" href="https://www.rowse-pneumatics.co.uk/blog/post/electric-vs-pneumatic-cylinders" target="_blank">both have their pros and cons</a>, so consider carefully which type would best suit your intended application.</p><p dir="ltr"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1721032215550-1721032215550.png" alt="Electircal Actuator" class="fr-fic fr-dii"></p><h3 dir="ltr">Speed</h3><p dir="ltr">Pneumatic actuators are typically capable of higher speeds than electrical ones. Both types can be fast in performance, but a pneumatic actuator offers higher duty cycles and faster reaction times. Pneumatic actuators usually take from 0.5 to 1.0 seconds to open or close a valve and also offer adjustable operating speeds.</p><h3 dir="ltr">Accuracy And Repeatability</h3><p dir="ltr">Pneumatic actuators currently offer lower accuracy and repeatability than electrical ones. This is because controlling air pressure is harder than controlling electric current and/or voltage. For extreme precision with pneumatic actuation – with control valves, for example – you may need to install an electro-pneumatic positioner to achieve accurate motion control.</p><h3 dir="ltr">Force</h3><p dir="ltr">Pneumatic actuators are capable of generating significantly higher force than electrical ones, which depends on the design and capacity of their mechanical components.</p><h3 dir="ltr">Design</h3><p dir="ltr">Pneumatic actuators are simpler in design – compact and with fewer components. They’re easier to install but may require more overall space to house peripherals. The components of electrical actuators, such as electric motors and ball screws, are more complex.</p><h3 dir="ltr">Environment</h3><p dir="ltr">Pneumatic actuators are designed to withstand higher pressures and temperatures, as they’re often used in harsh and hazardous environments. The delicate components in electric actuators require a greater level of protection to withstand high pressures and temperatures, as well as vibration and the ingress of moisture, dirt or dust. They might not function properly in hazardous environments, for which numerous certifications such as IP ratings are required.</p><h3 dir="ltr">Efficiency And Cost</h3><p dir="ltr">When comparing pneumatic and electrical actuators, pneumatic systems are typically cheaper to install and initiate. But their long-term running costs may eventually exceed those of electrical actuators, once replacement parts and energy costs are taken into account. You don’t need a motor to run a pneumatic actuator, but you will need electricity if you’re using a pilot valve or&nbsp;<a title="Solenoid Directional Control Valve" href="https://www.rowse-pneumatics.co.uk/blog/post/what-are-solenoid-valves" target="_blank">solenoid directional control valve</a>. Electrical actuators are more expensive to purchase, but their long-term running costs are usually lower and energy savings are more achievable.</p><h3 dir="ltr">Failsafe</h3><p dir="ltr">Many manufacturers offer double-acting pneumatic actuators with a built-in failsafe device, which you’d normally only find in spring-return models. A failsafe installed in a durable double-acting actuator kicks in if you lose power, signal or air pressure. In this event, it automatically engages built-in springs to return a control valve or other device to the normal or “safe” position. Failsafe features are available for electric actuators, but they’re not so easy to implement.</p><h2 dir="ltr">Pneumatic Or Electrically Actuated Ball Valves</h2><p dir="ltr">You might be comparing pneumatic or electrical actuators for specific situations such as flow control. When you need to control the flow of any media like air, gas or fluids, you might be looking at&nbsp;<a title="Ball Valves" href="https://www.rowse-pneumatics.co.uk/pneumatics/process-automation/ball-valves" target="_blank">ball valves</a>. In this circumstance, both types of actuation serve the same purpose.</p><h3 dir="ltr">Pneumatically Actuated Ball Valves</h3><p dir="ltr">Pneumatically actuated ball valves work with the two most common types of pneumatic actuators – the double-acting or the spring-return. Both are of reliable and durable rack and pinion design. Double-acting pneumatic actuators are likely to be up to 70% smaller than comparable industry-standard electrical versions.</p><h3 dir="ltr">Electrically Actuated Ball Valves</h3><p dir="ltr">Electrically actuated ball valves are also called rotary or motorised ball valves. They’re commonly powered by a motor, which will probably be of 12DC, 24DC or 120AC voltage, plus a gear train to generate the torque required for cycling the valve. They’re cheap to operate, offer flexible motion control and make minimal noise. On the downside, you’ll find them initially more expensive, slower than pneumatic actuation and lacking in failsafe options.</p><h2 dir="ltr">What Are The Essential Differences Between Pneumatic And Electric Actuators?</h2><p><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1721032215431-1721032215431.png" alt="Pneumatic Actuator" class="fr-fic fr-dii"></p><p dir="ltr">The essential differences between pneumatic and electric actuators boil down to available space, power source, operating temperature, lifespan and cost.</p><h3 dir="ltr">Space</h3><p dir="ltr">When space is limited, you’ll need an electric or double-acting pneumatic actuator. Electrical models are typically about 30% larger overall and pneumatic spring-return models are much wider than the double-acting type.&nbsp;</p><h3 dir="ltr">Power Source</h3><p dir="ltr">You’ll need a compressor to provide a 60-125 PSI air supply to run a pneumatic actuator. If it has a solenoid directional control valve, this will require AC or DC voltage supply. If air compression isn’t feasible for your application, use an electric actuator.</p><h3 dir="ltr">Operating temperature</h3><p dir="ltr">Pneumatic actuators are much more flexible concerning operating temperature. They can be rated to work at anywhere between -20°F and 350°F. Pneumatic actuators are also resistant to explosion, though you should be careful if a flush-mounted solenoid valve is installed. &nbsp;</p><p dir="ltr">High-temperature environments are more likely to cause overheating in electrical actuators, which are typically rated between 40°F and 150°F. They’re designed to comply with common&nbsp;<a title="NEMA Ratings" href="https://en.wikipedia.org/wiki/NEMA_enclosure_types" target="_blank">NEMA ratings</a> for specific operating environments, such as wet, dirty or hazardous areas. In all cases, ratings will depend on the specific product and the manufacturers’ rating criteria.</p><h3 dir="ltr">Lifespan</h3><p dir="ltr">Top-quality pneumatic actuators of the rack and pinion type can last up to around a million cycles when used within spec. Electric actuators are application-dependent, but mostly achieve only about a quarter of that.</p><h3 dir="ltr">Cost</h3><p dir="ltr">Depending on your application, you’ll generally find pneumatically actuated ball valve models less expensive than their electrical counterparts. As long as you use them within the prescribed specifications, they’ll last longer and may offer better overall value.</p><h2 dir="ltr">Should I Choose Pneumatic Or Electrical Actuation?</h2><p dir="ltr">Go for electrical actuators if you have no access to pressurised air or your application requires a slower cycle time. The rapid cycle times achievable with pneumatic actuators are inefficient in high-flow applications with liquid media. If you require greater speed and force, you should go for the more affordable pneumatic actuators. They’re simple to use, reliable, durable and resistant to most environments.</p>

If you’re using a general-purpose actuator for an application, various factors might affect your choice. These include your application’s requirements for speed, accuracy, repeatability and force, as well as the complexity of the actuator’s design and the environments in which you want to use it.

Pneumatic Vs Electrical Actuators

Pneumatic actuators convert compressed air into mechanical motion, enabling precise and efficient control in various industrial applications.

What are Pneumatic Actuators? Principles, Types, and Applications

<p dir="ltr" id="isPasted">Actuators are responsible for moving mechanisms in a system. Pneumatic and electric actuators have similar structures, &nbsp;the main difference between them being their power source. Pneumatic actuators derive their power from compressed air pressure while electric actuators rely on electricity to power their functions.</p><p dir="ltr">To understand the appeal of using electric actuators over their pneumatic counterparts, we need to compare their features:</p><h2 dir="ltr">Pneumatic Vs Electric</h2><h3 dir="ltr">Design</h3><p dir="ltr">Pneumatic actuators feature a simpler and more compact design than electric actuators, which are built with more components such as motors and a ball screw. Despite pneumatic actuators being more lightweight, the components required to regulate airflow to operate them can increase their size and weight.&nbsp;</p><h3 dir="ltr">Speed&nbsp;</h3><p dir="ltr">Pneumatic actuators operate with higher speed and lower force, but it’s difficult to maintain a consistent speed with compressed air. Pneumatic actuators are controlled manually, requiring specific adjustments to ensure the air force is accurate.</p><p dir="ltr">Electric actuators are operated through a program controller, giving the operator full control over speed when the device is in use. This is because electric actuators are powered by voltage, making them easier to moderate. In addition, the design of electric actuators with ball screws or pinion components reduces the gear ratio.</p><h3 dir="ltr">Accuracy</h3><p dir="ltr">Although pneumatic actuators can provide high speeds and force, their accuracy is not as precise as electric actuators. As they are powered by compressed air, they have less accurate positioning, limiting their position applications. For this reason, pneumatic actuators are often selected for simpler tasks with end-to-end position requirements. Electric actuators by comparison are highly accurate with positioning capability down to 0.0025mm, making them very efficient.</p><p dir="ltr">Electric actuators have a clear advantage over pneumatic devices. Because of their electric power source, they provide more precision and dependability in repetitive functions. Given their high efficiency, electric actuators can be used with various position applications. Electric actuators typically use either servo or stepper motors. These motors feature advanced stop function reliability and more torque control to prevent position drifting.&nbsp;</p><h3 dir="ltr">Environment and Safety</h3><p dir="ltr">Pneumatic actuators can handle hazardous or harsh environments better than electric devices because the latter’s electric components like sensors and motors are more sensitive. Pneumatics are also capable of handling a wider range of temperatures (-28 to 177 C) compared to electric actuators (-40 to 65 C). But pneumatic devices can still break down in high ambient temperatures if their air seals are damaged.&nbsp;</p><p dir="ltr">Electric actuators are affected by high heat, which erodes the bearing grease of the electric motor and metal expansion components, causing wear. There is also a concern about overheating with electric actuators because of their power source. Electric actuators are considered safer and more predictable for emergency stop functions because, unlike pneumatic devices, they don’t rely on air to hold a cylinder in position. Electric actuators also have a significant safety advantage because they automatically shut down if they experience an electrical short or overheat.</p><p dir="ltr">Electric actuators produce less noise than pneumatic devices, whose compressed air tanks generate more noise in the environment.&nbsp;</p><h3 dir="ltr">Costs and Maintenance&nbsp;</h3><p dir="ltr">Pneumatic actuators are more affordable to purchase upfront, although their maintenance costs can build up over time. Part of these costs will be the electricity to run compressed air tanks and maintain them. Electric actuators have a higher outlay cost, but they are less expensive to power. They can save on operation costs in the long run because air power takes more maintenance and is not as effective as electric power.</p><h3 dir="ltr">Data Collection</h3><p dir="ltr">With industry 4.0 tech paving the path for predictive maintenance and advanced automation, manufacturers are also seeking better data collection integration capacity. Electric actuators make it easier to collect data thanks to their in-built components and allow for enhanced real-time control. They are also compatible with many industrial network protocols used for communication (eg EtherNetIP, EtherCAT, Profinet). Pneumatic actuators have similar data monitoring capability although not to the same degree as electric actuators.</p><h2 dir="ltr">So Are Manufacturers Moving Away From Pneumatics?</h2><p dir="ltr">Evaluating electric and pneumatic actuators side by side, it’s clear that electric actuators do have an advantage in performance and reliability. But pneumatic actuators are not redundant in the industry – the choice a manufacturer makes between pneumatic and electric actuators will be decided by their requirements. It’s also worth noting that pneumatic actuators are being developed to incorporate similar control features to electric actuators.&nbsp;</p><p dir="ltr">The choice of pneumatic or electric actuators is determined by the functions the device will carry out. Pneumatic actuators are suited to simple end-to-end positioning with a single axis. They are also preferable for functions that require limited motion profiles because pneumatic profiles are more difficult to change once configured.&nbsp;</p><p dir="ltr">For more complex functions that require high accuracy and dependability in repeating motion profiles, electric actuators are the better choice. They are also more efficient in emergency stop applications because of their precise torque control and speed variation capacity.</p><p dir="ltr">Whether a manufacturer chooses pneumatic actuators over electric devices is ultimately determined by a range of factors – notably accuracy, costs and long-term maintenance. Pneumatic actuators are cheaper upfront, but their upkeep and running costs do add up. Although electric actuators may appear to have more advantages, they do have higher costs and are not as capable of enduring harsh conditions as pneumatic components.</p><p dir="ltr">In conclusion, pneumatics are not redundant, they are just better suited to simpler functions. Economic factors such as the trend in cost reductions are influencing the choice manufacturers make, which accounts for the move to electric actuators. Saving energy while achieving high accuracy across a wide range of functions are two distinct advantages of using electric over pneumatic devices. Regardless of these benefits, pneumatic actuators will still be needed for specific cases.</p>

Manufacturing industry trends have seen a rise in the use of electric actuation over pneumatic, which has raised questions about whether pneumatic actuators are slowly being phased out.

Is Pneumatics Dying?

<p id="isPasted">Applications now extend to process manufacturing of electronic devices, aerospace and defence, where pneumatic cylinders have provided a crucial tool for engineers. If you’re working in one of these industries, here’s all you need to know about pneumatics for clean rooms.</p><p>A clean room is a contained space where particulate contamination is intentionally reduced to a minimum. Other environmental parameters are also controlled, such as air pressure, humidity and temperature. A High Efficiency Particulate Air (HEPA) filter is installed in the clean room to trap any particles sized 0.3 microns or more. In cases where even more stringent performance is required, Ultra Low Particulate Air (ULPA) filters may be used. All the air that’s supplied to a clean room will first have passed through these filters.</p><h2>Contamination</h2><p>In the sterile environment of the clean room, a dust mote is the equivalent of a boulder. Even the tiniest particle of dirt or moisture can be catastrophic. So engineers were always careful about what actuators they chose to equip a clean room. Pneumatic cylinders originally constituted sources of contamination, including tiny chunks of abraded material or particles of lubricant, aerosol or chemical vapours.</p><p>New designs developed in the 1990s solved these problems, introducing&nbsp;<a href="https://www.rowse-pneumatics.co.uk/pneumatics/pneumatic-drives" title="Pneumatic Drives" target="_blank">pneumatic cylinders</a> that largely replaced electric motors in the clean room environment. They were cleared for use in ISO 14644-1 rated clean rooms in class ISO 4, which stipulates that only 352 particles of this size are allowed in a cubic metre of air. This is about one millionth of the number of equivalent particles in ambient room air. All clean room products are now classified into grades according to ISO 14664.</p><h2>Developing Pneumatics For Clean Rooms</h2><p><img data-fr-image-pasted="true" src="https://www.rowse-pneumatics.co.uk/static/images/blog/posts/All-You-Need-To-Know-About-Pneumatics-For-Clean-Rooms-1.jpg" alt="Everything You Need To Know About Pneumatics-For-Clean-Rooms" class="fr-fic fr-dii"></p><p>Until this century, using pneumatics in an ISO 4 clean room would have been inconceivable. Electric motors were used because all their moving parts were enclosed. This meant that any random particles were contained, and there was minimal air turbulence. The breakthrough in pneumatics for clean room applications was to create an actuator that could equal or improve on this performance.</p><p>Pneumatics engineers worked to improve the design of the rodless cylinder, to eliminate features that allowed particulates to get out. These cylinders had previously contained an aluminium barrel with a slot in one side, through which dirt, dust and lubricants could escape into the surrounding atmosphere. New designs reduced these emissions and slowed down load movement, so the airflow wasn’t disturbed to stir up existing particles.</p><p>The new generation of air cylinders had the same capabilities as an electric motor, but added advanced positioning accuracy of one ten-thousandth of an inch. They still retained the traditional advantages of pneumatics, such as high speed, high force and low cost.</p><p>The new generation of air cylinders had the same capabilities as an electric motor, but added advanced positioning accuracy of one ten-thousandth of an inch. They still retained the traditional advantages of pneumatics, such as high speed, high force and low cost.</p><h2>Expanding The Application</h2><p>The improved pneumatic cylinders hit the market in the mid-1990s, and enhanced their suitability for clean rooms in three critical ways: they were cleaner, much more rigid for larger loads and provided precise positioning capabilities. This innovation kicked off an important trend in pneumatics, making air cylinders a viable alternative to stepper motors.</p><p>Today, clean room production has extended beyond semiconductor manufacturing and electronics, into many other industries. The number of pneumatic products that are suitable for use in clean rooms has also expanded considerably.</p><p><a href="https://www.rowse-pneumatics.co.uk/manufacturers/view/festo?filters=actuation_type=Pneumatic" title="Festo" target="_blank">Festo&nbsp;</a>, for example, produce a range of equipment that includes cylinders, drives, valves, grippers and all sorts of vacuum, handling and compressed air systems. Components such as sensors, compressed air regulators, filters and fittings are available in 80+ product ranges that are rated for ISO-classified clean room environments.</p><h2>Choosing Clean Room Products</h2><p>Clean rooms are rated under the ISO 14644-1 classification system, according to the cleanliness of the air inside. The standard stipulates the size and maximum number of particles that may be allowed per cubic metre of air. Clean room classes rated under this standard range from ISO1 to ISO9, where 1 is the cleanest and 9 is the most contaminated class. However, even an ISO9 clean room is less contaminated than an ordinary room. Clean room classes 7 and 8 are the most common.</p><p>The associated standard ISO 14644-14 rates any products that you wish to use inside the clean room with the correct classification for the rating of the room itself. Clean rooms are not uniformly rated, however, and varying levels of cleanliness apply to different areas. It’s possible, for example, to have a general workflow area rated in class 7, while the area directly above a workpiece needs to be rated in class 5. Clean room products are therefore classified according to where they’ll be used in the application.</p><p>When purchasing pneumatic products for use in clean rooms, be sure to match the ISO rating of the product with the ISO rating of the area in which you wish to use it. This might mean you end up with a variety of products in different classes, but that depends on the manufacturer. Festo, with whom we have an official partnership, have issued a separate clean room catalogue, which classifies all their pneumatic products according to their area of use. Although these are generally rated ISO 7, most of them can be used in class 6 and 5 environments, and some even in class 4.</p><h2>Expanding Market</h2><p>Clean rooms are now common throughout industry, wherever a manufacturing process is impacted by particulate contamination. They come in all sizes and degrees of complexity and are critical to the micro-processes required by modern technologies. You’ll find clean rooms used extensively in industries like medical device and life sciences, biotech, pharmaceuticals and semiconductor manufacturing.</p><p>They’re also used for the type of critical process manufacturing that you’ll see in nanotechnology, optics and photovoltaic engineering, plus energy, aerospace and military applications. In the last few decades, pneumatics have made significant inroads into the market for clean room rated products, providing a cheaper and more efficient solution to eradicating particulate contamination.</p>

All You Need To Know About Pneumatics For Clean Rooms

In the last century, very few industries needed a clean room, but modern technology changed all that. Microelectronics manufacturing, biotechnology, pharmaceutical, medical and the processing of food and beverages all demand absolute sterility.

<p id="isPasted">The premise at that time was that design engineers might be moving away from pneumatics, but that pneumatics could continue to grow as an industry if approached in the right manner.</p><p>The recommendation was for a seamless integration of pneumatics and automation, that would rely heavily on IIoT adoption and more compact, efficient machines. The presenter, Donna Ritson of DDR Communications, outlined how pneumatics might continue to advance using smart technologies and data collection. Pneumatic applications would require effective data gathering and manipulation, remote servicing, preventive maintenance, more efficient machines – and much more – in order to increase their level of intelligence.</p><p>The goal was to achieve a greater level of automation so that pneumatic and automation systems work together. This would require intuitive and interactive HMIs: as factories become more automated, they have less skilled labour. What operators there were would want simpler machines that were more intuitive. The idea was that the machinery itself should provide the initiative for preventive maintenance, by setting off alerts and alarms for the operator. Smarter sensors would be installed to tell workers when a component is wearing out and what adjustments or responses needed to be made.</p><h2>Pneumatic And Automation Systems Working In Harmony</h2><p>Since the 2018 conference, the automation industry has made&nbsp;<a href="https://www.rowse-automation.co.uk/blog/post/what-is-industrial-automation" target="_blank" title="What Is Industrial Automation?">great advances</a> in digital transformation. The idea of pneumatics becoming outdated has itself become obsolete thanks to the integration of evolving pneumatic technologies. These include control valves that incorporate sensors, wireless technology and industrial network interfaces.</p><p>Complex digital control features offer access to smarter, actionable information that significantly improves the efficiency of automation applications. Plug-in valves and manifolds were also created, which meant that all the solenoid valve connections which were previously linked separately to the PLC could be achieved using a single cable. Integrating&nbsp;<a href="https://www.rowse.co.uk/blog/post/what-is-iiot" title="What Is IIoT?" target="_blank">IIoT technology</a> means that pneumatic valve systems now incorporate much more advanced electronic features, providing pneumatic-driven actuators and applications with a whole new level of precision control.</p><p>Valve system control modules for pneumatic positioning applications are able to incorporate proportional-integral-derivative (PID) controllers, which can automatically monitor and adjust control functions. Such high-tech pneumatic capabilities allow greater precision in end-point motion accuracy. Used in conjunction with a PLC, they also have the capacity to switch in real time from position control to force control. Motion sequences for very advanced automation tasks can be accurately fine-tuned, increasing reliability, repeatability and product throughput.</p><p>Automation systems continue to evolve into a more sophisticated, connected partnership with pneumatic applications. Industrial network communications were established via fieldbus connectivity, increasing the control capabilities of a PLC. As well as controlling valves, the newer PLCs can also monitor sensors and other connected devices. Instead of several local I/O cards, they are able to exchange I/O data via a single communication cable.</p><h2>Evolution Of Smart Pneumatics</h2><p>As the automation platforms became smarter and more sophisticated, so did&nbsp;<a href="https://www.rowse-pneumatics.co.uk/blog/post/what-is-smart-pneumatics" target="_blank" title="What Is Smart Pneumatics?">pneumatics</a>. Design engineers began to incorporate both I/O capability and fieldbus interfaces into pneumatic valve manifolds. These provided complete pneumatic valve packages, far more versatile than previous discrete components and engineered to be easily integrated into advanced automated systems.</p><p>A further step forward in valve technology came with the integration of electro-pneumatic control capabilities into the valve manifold. This greatly enhanced their versatility and performance capabilities. New technologies also allowed more accurate control of proportional regulators using digital signals. Fieldbus connectivity integrated into these devices was also able to optimise the force and pressure requirements in any given production system.</p><h2>Why It’s Important</h2><p>In the 2018 survey, manufacturers wanted pneumatic components that were more robust, durable and energy-efficient, as well as easily and reliably available. They asked for smoother and more user-friendly pneumatic systems that would increase motion and speeds and offer better precision. And with all that, they wanted pneumatic components that were easier to maintain, more compact and, most of all, repetitive.</p><p>Ritson noted in her presentation that all these pneumatic technologies had already been developed in 2018. For example, cylinder-mounted and linear slide sensors were already designed with continuous position sensing and supported rapid maintenance and replacement. But what was more interesting from the point of view of the survey, was the gap between the perception of the end users and reality.</p><p>Although the technological capabilities already existed, one of the biggest challenges for suppliers was to educate the industry about its existence. Many end users were not aware that the technology was available and consequently had failed to invest in these advanced solutions. Ritson concluded that more companies needed to connect the capabilities of pneumatics and automation systems working together and install smarter machines in their facilities.</p><h2>This Is The Future Of Manufacturing</h2><p>One of the primary objectives of digital transformation in manufacturing in particular, and the&nbsp;<a href="https://www.rowse-automation.co.uk/blog/post/what-is-industry-4" target="_blank" title="What Is Industry 4.0?">IIoT in general</a>, is the collection of actionable information. In manufacturing, it provides more sophisticated and optimised control, step by step throughout the production process. For example, pneumatic valve systems with built-in intelligence offer new opportunities for such precision monitoring and control.</p><p>A well-designed predictive maintenance system integrated into a valve can capture and use minutely accurate information that will optimise and prolong the working life of pneumatic applications. If the system determines that a component is in imminent danger of failure, it may even implement an automated requisition for a replacement before that actually happens.</p><h2>More Productive, Cleaner And Energy-Efficient</h2><p>As pneumatic components become smarter, they’re able to generate many more data points to improve the production systems in which they’re used. These data points include usage statistics, diagnostics and lifetime data, which can be used to maximise uptime in production systems, control their energy consumption and make systems run more efficiently.</p><p>The advanced level of control achieved by combining pressure and directional controls greatly increases the versatility of pneumatics. It also enhances its value for a much greater range of automation applications. Smart pneumatics provides more precise, efficient and optimised control for automated applications in the manufacturing process.</p><p>When pneumatics and automation work together, factories become more productive, cleaner and energy-efficient.</p>

How Pneumatic and Automation Systems Work Together

Five years ago – a long time in technological terms – “The Evolution of Advanced Automation” was discussed in a presentation at the Industry & Economic Outlook Conference in the United States, held by the National Fire Protection Association.

<p dir="ltr" id="isPasted">Soft robotics is a rapidly advancing field of robotics that involves the design and development of robots made from flexible and deformable materials. These robots, unlike their traditional rigid counterparts, have the ability to adapt to their environment, navigate complex and dynamic spaces, and interact safely with humans. Soft robots can be made from materials such as silicone, rubber, and other flexible polymers, and they can be made to resemble a wide range of shapes and structures.&nbsp;</p><p dir="ltr">In this article, we list out and explain in detail the different types of actuators used in soft robotics, including pneumatic, hydraulic, shape memory alloys, electro-active polymers, and magnetic fields. We also explore some applications of soft robotics enabled by them.</p><h1 dir="ltr">Introduction</h1><p dir="ltr">Since the early days of robotics, the focus has been on rigid and inflexible machines capable of performing specific tasks with high speed, high accuracy, and high repeatability. However, the limitations of traditional robotics eventually became apparent in specific fields, such as medicine, manufacturing, and disaster response, where safety and flexibility were critical.</p><p dir="ltr">Further research in the domain led to the creation of soft grippers and other soft components that could let the robots interact with their environment in a much better way.&nbsp;</p><p dir="ltr">With the rise in popularity of biomimetics, the study of nature that inspires the design and development of new technologies, researchers have increasingly drawn inspiration from the behavior of biological entities to come up with creative ideas for the development of new and innovative robotic systems.</p><p dir="ltr"><em><strong>Suggested reading: </strong></em><a href="https://www.wevolver.com/article/biomimetics-the-science-of-robo-animals" target="_blank"><em>Biomimetics: The Science of Robo-Animals</em></a></p><p dir="ltr">Advancements in material science and fabrication techniques, such as 3D printing, enabled the development of more complex soft robots that could be applied in various areas like biomedical devices, wearables, and disaster response.<sup>[1]</sup></p><p dir="ltr">In the early 2010s, Prof. George Whitesides from <a href="https://www.wevolver.com/profile/harvard.university" target="_blank">Harvard University</a> coined the term &ldquo;soft robotics&rdquo;.<sup>[2]</sup> IEEE Robotics and Automation Society established a new technical committee for soft robotics to promote research in the domain, and since then, the field has continued to evolve.<sup>[3]</sup></p><h1 dir="ltr">Types of Actuators Powering Soft Robots</h1><p dir="ltr">Soft robots need power sources to drive the actuation of their moving parts. Actuation is the process of generating movement in a robot, and it is necessary for soft robots to be able to move and interact with their environment. Here are the different types of actuators powering soft robotics:</p><h2 dir="ltr">Pneumatic and Hydraulic actuators</h2><p dir="ltr">Just as electric motors require a power source, such as a battery or an external power supply, to drive the robot&#39;s movement, hydraulic and pneumatic systems require a source of pressurized fluid, such as air or water.</p><p dir="ltr">Pneumatic actuators use compressed air to generate force and motion. They are often made of flexible materials such as rubber or silicone and can be shaped to fit a variety of applications. Pneumatic artificial muscle made of a flexible tube can expand when pressurized and produce a contracting force when depressurized.</p><p dir="ltr">Hydraulic actuators, on the other hand, use a liquid such as water or oil to generate force. They can produce higher forces than pneumatic actuators and are often used in industrial automation applications. In soft robotics, hydraulic actuators are made of flexible materials.</p><p dir="ltr">While pneumatic actuators are lightweight and easy to control, they may not be as powerful as hydraulic actuators to drive a soft robot. Hydraulic actuators generate more force but require additional components, such as pumps and reservoirs, to function, which can add significant complexity to the design.&nbsp;</p><p dir="ltr"><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe width="640" height="360" src="https://www.youtube.com/embed/_4BTGgJjHog?&ab_channel=NASALangleyResearchCenter&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span><br>Pneumatic and Hydraulic actuators may also incorporate sensors and feedback mechanisms to enable precise control. Ultimately, the choice of the actuator depends on the specific requirements of the soft robot being developed.</p><h2 dir="ltr">Shape-memory alloys</h2><p dir="ltr">Shape-memory alloys (SMA) are unique actuators that change shape when exposed to heat. This method also requires a power source, such as a battery or an external power supply, to generate the electric current for heating up the alloy.</p><p dir="ltr">SMAs can be bent or deformed into a particular shape, and when they are heated, they will return to their original shape, generating a mechanical force. This property makes them useful for soft robotic systems that require high force and precision, such as those used in biomedical devices and prosthetics.</p><p dir="ltr">Some commonly used SMAs are Nitinol (Nickel-Titanium alloy), Copper-Aluminum-Nickel alloys, Iron-Manganese-Silicon alloys, Copper-zinc-aluminum alloys, etc. Overall, SMAs have a number of useful properties, including less weight, flexibility, and the ability to generate high forces, making them a promising power source for developing soft robotic devices.</p><p><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe width="640" height="360" src="https://www.youtube.com/embed/lbJHa9QL0D8?&ab_channel=HarrisonYoung&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span></p><h2 dir="ltr">Electro-active polymer actuators</h2><p dir="ltr">Electro-active polymer (EAP) actuators use an applied electric field to generate mechanical deformation. EAPs are a promising technology for use in soft robotics, as they offer several advantages over other types of actuators.</p><p>The key advantages of EAP actuators are their softness and flexibility. EAPs can be fabricated into a variety of shapes and sizes, making them well-suited for use in soft robots. Additionally, EAPs have the potential to be more lightweight and energy-efficient than traditional actuators, which can be crucial in applications where weight and power consumption are critical.</p><p>There are several types of EAP actuators, including dielectric elastomer actuators (DEAs), ionic polymer-metal composites (IPMCs), and conductive polymers. Each of these types of EAP actuators works by a different mechanism, but all of them involve the use of an applied electric field to generate mechanical deformation.</p><p>DEAs, for example, are made of a thin layer of a soft, electrically insulating polymer sandwiched between two layers of compliant electrodes. When an electric field is applied to the electrodes, it causes the polymer to deform, generating a change in shape or volume. This deformation can be used to drive the movement of a soft robot.</p><p>IPMCs are made of a thin layer of an ion-containing polymer sandwiched between two layers of metal electrodes. When an electric field is applied, the ions in the polymer move towards one of the electrodes, causing the polymer to bend. This bending can be used to generate movement in a soft robot.</p><p>Conductive polymers are a third type of EAP actuator that use the conductivity of the polymer to generate mechanical deformation. When an electric field is applied to a conductive polymer, it causes the polymer to expand or contract, depending on the strength and the direction of the field. This deformation can be used to drive the movement of a soft robot.</p><p>EAP actuators offer a promising avenue for actuation in soft robotics; however, there are still several challenges that need to be addressed to fully realize their potential in soft robotics, such as improving their durability and scalability.</p><h2 dir="ltr">Magnetic actuators</h2><p dir="ltr">Magnetic actuators, as the name suggests, are actuators that use magnetic fields to generate movement. They consist of a magnet embedded in a flexible, elastomeric material. When a magnetic field is applied to the magnet, it causes the elastomer to deform, which drives the movement of a soft robot.</p><p dir="ltr">One of the advantages of magnetic actuators is that they are relatively simple and inexpensive to fabricate. They also offer a high degree of precision and control, which can be important in certain applications.</p><p dir="ltr">In soft gripper applications, magnetic actuators are used to generate the force needed to grasp and manipulate objects. By adjusting the strength and direction of the magnetic field, the grip force of the gripper can be finely tuned to the requirements of the task. In soft manipulator applications, magnetic actuators are used to drive the movement of the manipulator, allowing it to perform tasks such as grasping and releasing objects. In sensor applications, magnetic actuators are used as the sensing element, allowing the robot to detect and respond to changes in its environment.</p><p dir="ltr"><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe width="640" height="360" src="https://www.youtube.com/embed/OXRmxuB60DQ?&ab_channel=naturevideo&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span><br>One of the challenges of using magnetic actuators in soft robotics is the need for a strong and consistent magnetic field, which can be difficult to achieve. Additionally, the design of the magnetic actuator can affect its performance, and optimizing the design can require a significant amount of time and resources.</p><h1 dir="ltr">Applications of Soft Robots</h1><p dir="ltr">Soft robotics is an emerging field that has the potential to revolutionize a wide range of industries. Here are some of the applications of soft robotics:</p><ul><li dir="ltr"><p dir="ltr"><strong>Healthcare: </strong>Soft robots can potentially transform healthcare by enabling new forms of minimally invasive surgeries. The technology can also be used to build exosuits that help people with disabilities regain mobility. When used for making prosthetics, soft components can provide a more natural and comfortable fit for amputees.</p></li><li dir="ltr"><p dir="ltr"><strong>Manufacturing:</strong>&nbsp;Soft robots are well-suited for manufacturing applications that require delicate handling of objects. They can also be used in assembly line operations to handle fragile components or to package products more efficiently and gently.</p></li><li dir="ltr"><p dir="ltr"><strong>Survey and exploration: </strong>Soft robots can make their way through challenging environments such as underground mines, deep-sea environments, and space. Their softness and flexibility enables them to adapt to different obstacles and <a href="https://www.wevolver.com/article/connectivity-and-sensing-technologies-proven-in-the-harshest-environments" target="_blank">harsh environments</a>.</p></li><li dir="ltr"><p dir="ltr"><strong>Agriculture: </strong>Soft robots can be used in agriculture to perform tasks such as planting, harvesting, and weeding. They can navigate through the fields without damaging crops. When used in conjunction with sensors and machine learning algorithms, these robots can prove to be a great help.</p></li><li dir="ltr"><p dir="ltr"><strong>Search and Rescue: </strong>Soft robots can be used in search and rescue operations to locate and extract people from collapsed buildings or search for survivors in areas inaccessible to traditional search and rescue equipment.</p></li><li dir="ltr"><p dir="ltr"><strong>Entertainment:</strong>&nbsp;Soft robots can be used in theme parks, animatronics, and other interactive means of entertainment to provide a more lifelike and engaging experience for users. They can also be possibly used to create new forms of entertainment.</p></li><li dir="ltr"><p dir="ltr"><strong>Education:</strong>&nbsp;Soft robots can also be used in educational settings to teach students about robotics and engineering. The teachers can demonstrate concepts such as motion, force, and control and inspire students to pursue careers in science and technology.</p></li></ul><p dir="ltr">These are just a few of the many applications of soft robotics. As research in this field continues to advance, we will likely see many new and exciting applications in the future.</p><h1 dir="ltr">Conclusion</h1><p dir="ltr">The development of advanced and sustainable power sources is key to unlocking the full potential of soft robotics and enabling these innovative machines to change the way robots interact with their environments.&nbsp;</p><h1 dir="ltr"><em>About the sponsor: Mouser Electronics</em></h1><p dir="ltr"><em>Mouser Electronics is a worldwide leading authorized distributor of semiconductors and electronic components for over 1,200 manufacturer brands. They specialize in the rapid introduction of new products and technologies for design engineers and buyers. Their extensive product offering includes semiconductors, interconnects, passives, and electromechanical components.</em></p><p dir="ltr"><em><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1678247690451-1678247690451.png" width="720" height="91" class="fr-fic fr-dii"></em></p><h1 dir="ltr">References</h1><p dir="ltr">[1] Wallin, T.J., Pikul, J. &amp; Shepherd, R.F. 3D printing of soft robotic systems. Nat Rev Mater 3, 84&ndash;100 (2018). <a href="https://doi.org/10.1038/s41578-018-0002-2" style="background-color: transparent;" target="_blank">https://doi.org/10.1038/s41578-018-0002-2</a></p><p dir="ltr">[2] Carl Vause, &lsquo;This robot has soft hands. It could be the future of sustainable production&rsquo;, World Economic Forum, 21 June 2018, [Online], Available from: &nbsp;<a href="https://www.weforum.org/agenda/2018/06/robot-soft-hands-sustainable-production-soft-robotics/" style="background-color: transparent;" target="_blank">https://www.weforum.org/agenda/2018/06/robot-soft-hands-sustainable-production-soft-robotics/</a></p><p dir="ltr">[3] IEEE Technical Committee for Soft Robotics, [Online], Available from <a href="https://www.ieee-ras.org/soft-robotics" target="_blank">https://www.ieee-ras.org/soft-robotics</a></p>

As the field of soft robotics continues to evolve, one of the most critical challenges researchers face is developing reliable and efficient power sources to drive these pliable machines.

Powering Soft Robotics: A Deeper Look at Soft Robotics Actuators

Robotic actuators are the muscle power of Industry 4.0

Robotic actuators stand at the forefront of technological innovation, transforming energy into motion to breathe life into robots, enhancing their capabilities in an ever-evolving landscape of industrial automation.

Robot Actuators: A Comprehensive Guide to Types, Design, and Emerging Trends

Actuators are an integral part of instrumentation systems that power the machines that exist today. These devices make it possible for the machines to interact with their surroundings the way they do. In this article, we take a closer look at the omnipresent technology.

What is an Actuator? Types, Principles, and Applications

Industry 4.0 is changing the traditional way that manufacturing and production are accomplished, and a positive turn towards clean energy means that more and better air-driven components are available.

The Ultimate Pneumatics Guide

<p>Plain atmospheric air is the most commonly used for compression; there's plenty of it, and in itself, it costs nothing. Pneumatic systems are generally preferred in industry and manufacturing over hydraulic systems, because they're quieter, cheaper to run and easy to use.</p><h1>What Is Pneumatics?</h1><p>Pneumatics is the blanket term for the physical science of compressing air, and for the branch of mechanical engineering that deals with the use of <strong>compressed air or gas</strong>. Pneumatics was originally as simple as compressing the air in your lungs by taking a deep breath, and then blowing it out forcefully to do something like igniting sparks for a fire or shooting a sharpened dart out of a tube.</p><h2>Common Parts Of A Pneumatic System</h2><p>The most common parts of a pneumatic system are:</p><ul><li>Drives</li><li>Valves</li><li>Fittings</li><li>Tubing &amp; Hoses</li><li>Vacuum Technology</li><li>Air Preparation (Filters, Regulators &amp; Lubricators)</li><li>Silencers</li></ul><hr><h3>DRIVES/CYLINDERS</h3><p>Pneumatic systems work by converting force into potential energy, which then drives an actuator or <a href="https://www.rowse-pneumatics.co.uk/help-advice/how-to-choose-a-pneumatic-cylinder/" target="_blank" title="Pneumatic Cylinders">cylinder</a> with kinetic energy. This is usually in a linear motion by means of a piston rod, or using other forms of actuation commonly called 'rodless'. The piston rod produces a simple up-and-down or back-and-forth motion, and the rod can be pushed either via a single action or a double-action stroke.</p><p>In single-acting pneumatic cylinders the compressed air drives the linear motion of the piston rod in one direction only. At the end of the stroke, a vacuum is created by expelling the compressed air, so the piston rod can make the return stroke via a mechanical spring. Double-acting cylinders allow the load to work in a push-pull motion, manipulating the compressed air with valves to drive the piston rod out and back. This can increase the length of stroke achievable, as well as enabling constant force to be maintained on alternating movements.</p><p>Rodless cylinders work in several different ways, including linear slide, magnetic coupling, inflatable bellows and rotary vane pump. The load is usually situated on a carriage alongside the piston, and they are often chosen for applications requiring a long stroke action or having high moment loads.</p><hr><h3>VALVES</h3><p><strong>Valves are used in pneumatics to control and direct the airflow</strong>, and have many different functions. When you start up the system, you might use a soft start or a simple on-off valve, and you can control the rate of the airflow with flow control valves. For controlling flow direction, there are ball valves and angle seat valves, and you can use pilot valves to control a separate, secondary system.</p><p>When you need to vent the system you'll use an exhaust valve. To close it down requires a shut-off valve, and to initiate an emergency stop you'll need a safety dump valve. All these types of valve release the air pressure from the system at specified times.</p><p>Simple air valves control the inward and outward flow of air into the pneumatic system, requiring some motivating force to direct or position the flow. If this force is applied directly to the operating medium, it's a direct-operated valve rather than a pilot or secondary valve. Other simple valves are the two-position flow control valves, which are either on or off.</p><p>Flow and directional control valves are self-explanatory, but there are also versions which allow three-way directional control from the inlet to either of two outlet ports, and the more complex four-way valve. This can direct flow from the inlet to a choice of three outlet ports. Proportional valves are electronically actuated using solenoids, and can alter the flow rate or pressure of the output in accordance with those of the inlet. This type of valve is used for more complex operations with one or more outputs, where fluid pressures and flow need to be distributed in varying ratios.</p><p>It's also increasingly common in modern pneumatics to use solenoid valves, and today's complex systems have given rise to universal valve terminals which enable modular valve configurations. The use and <a href="https://www.rowse-pneumatics.co.uk/pneumatics/valves" target="_blank" title="Pneumatic Valves">choice of valves</a> has therefore become quite a complicated undertaking, so as to provide simultaneous control of many advanced and specific situations.</p><hr><h3>FITTINGS</h3><p>Pneumatic systems comprise many components, and they all need to be joined together with fittings. <a href="https://www.rowse-pneumatics.co.uk/help-advice/choosing-pneumatic-fittings/" target="_blank" title="Pneumatic Fittings">Pneumatic fittings</a> join together the major system components with their requisite hoses, pipes and tubes, conducting the compressed air to the active parts of the application. The whole system is operating under the pressure of compressed gas or air, so all its component parts require tight, leak-proof seals and must fit together compatibly.</p><p>Fittings come in all shapes, types and sizes, are made of various materials, and have different ways of joining together. Fittings that use metal screw-in threads are still considered to provide the tightest bond, though other materials like polymers are also now used. Pipes that are of different size or type may be joined using compression fittings, while barb fittings are often chosen to join flexible tubing. These have a threaded end which connects to the pipe, and a single or multiple barbed cone which goes into the tube. Many people prefer the modern solution of push-in fittings, which are often used for joining air hoses. Their quick connect and disconnect design enables the easy change-over of different parts, and they come in many sizes and materials.</p><hr><h3>TUBING AND HOSES</h3><p>Tubing and hoses in a pneumatic system are two different things: <strong>hoses are typically used in high-pressure applications</strong> and are reinforced for extra strength; <strong>tubing, on the other hand, tends to be used in applications requiring lower pressure</strong>, and does not need reinforcement. Both come in many different types, with flexible pneumatic tubing or hoses being more widely used than the rigid ones. The development of strong polymers and application-specific materials make flexible tubes and hoses the most versatile parts of a pneumatic system. All you need to do is ensure that you have the <a href="https://www.rowse.co.uk/blog/post/how-to-choose-the-right-air-hose" target="_blank" title="How To Choose The Right Air Hose">right size and type</a> of hose or tubing for your devices, and that everything is compatible.</p><hr><h3>VACUUM TECHNOLOGY</h3><p>Creating a vacuum produces conditions where the air pressure is substantially below that of atmospheric air, specifically <strong>a negative pressure of 300 mbar or less</strong>. The available vacuum range is then subdivided into four categories, ranging from rough to ultra-high vacuum. In order to create a vacuum, it's necessary to remove all the air from a contained space, for which you can use a <a href="https://www.rowse-pneumatics.co.uk/pneumatics/vacuum/generators" target="_blank" title="Pneumatic Vacuum Generators">vacuum generator</a> connected to your pneumatic system. This ejects compressed air forcibly through a diffuser, leaving a vacuum in the application. The item on the workspace will then be drawn up into the vacuum by means of a <a href="https://www.rowse-pneumatics.co.uk/pneumatics/vacuum/gripping-technology" target="_blank" title="Gripping Technology">suction pad or cup</a>, and gripped there while it is processed.</p><p>Many fields of modern industry and various manufacturing processes are now using vacuum technology, including food and beverages, pharmaceuticals, metallurgy and process engineering. They are typically used for delicate pick and place applications, such as plate glass and small electronic components, or for gripping and holding items in position. One of the most recognisable uses for this technology is vacuum packaging.</p><hr><h3>AIR PREPARATION</h3><p>When air is compressed it heats up, and when it cools again it produces condensation which contaminates the supply of compressed air. Ordinary atmospheric air also generally contains impurities such as dirt, dust, oil and other particulates. If compressed air containing such contaminants is passed downstream into functioning parts of the pneumatic system, such as cylinders, valves and hoses, it will inevitably cause some damage. Even if your compressor has built-in components for filtering, drying or regulating the air intake, fittings and components along its outward journey to the application can contribute further contamination.</p><p>In order to keep your system functioning properly for as long as possible, therefore, <strong>it’s necessary that the compressed air supply is filtered</strong>. It is possible to install a simple air filter for this purpose, but the air will still have to be monitored to make sure that the correct pressure is being maintained. Furthermore, the compressed air will need to be lubricated so that downstream equipment is not damaged by an excessively dry air supply. So while all these functions can be dealt with by separate units for filtration, regulation and lubrication, it's more common these days to install a combined <a href="https://www.rowse.co.uk/blog/post/6-things-about-pneumatic-frls" target="_blank" title="6 Things To Know About Pneumatic FRLs">Filter-Regulator-Lubricator unit</a> (FRL).</p><p>For optimal performance of your pneumatic system, you should ensure that the air preparation takes place at the point of use for the machinery. This is particularly important if the compressor is a long way away from it, and provides opportunities en route for the build-up of more water and particulates. FRL units are today's integrated solution to the preparation of air, offering a broad range of filtration options, operating pressure regulation and lubrication where required. They are space-saving and cost-effective, and – if properly sized and installed – will give your pneumatic system a much longer, trouble-free working life.</p><hr><h3>SILENCERS</h3><p><a href="https://www.rowse-pneumatics.co.uk/pneumatics/silencers" target="_blank" title="Pneumatic Air Silencers">Pneumatic air silencers</a>, like the silencer on your car's exhaust, are simply a means to <strong>reduce excess noise when air is exhausted from your pneumatic system</strong>. Venting the exhaust air from a pneumatic system often makes an explosive sound, depending on the force and pressure of the flow. This increases the operational noise levels of the application as a whole, and can cause physical damage or disturbance to personnel. Installing a silencer is a cost-effective solution which can be fitted on pneumatic cylinders, 5/2-way solenoid valves, or other associated devices and fittings.</p><p>In addition, silencers can manage the airflow rate out of the unit using adjustable throttle valves. These work in a similar fashion to needle valves and can also control actuator speed. Further, the exhaust air may also contain contaminants, so an exhaust cleaner may be added to the silencer unit to protect the environment from any harmful particulates.</p><p><br></p>

Pneumatic systems are widely used in all sorts of machines, engines and industrial applications. Every pneumatic system runs on compressed air or gas, in order to move an actuator, and can be as simple as a single air-driven piston, or as complex as a mining operation with multiple actuators.

What Is Pneumatics?

<p>While some actuators and lifting devices can be purely electrical, using a screw system, it's far more likely that you'll be using some form of fluid power. This means you have a choice between hydraulics and pneumatics.</p><p>Pneumatics provides fluid power by means of pressurised air or gases. Hydraulics provides fluid power by means of pressurised liquids, such as oil or water. In choosing one of the two, cost-effectiveness, materials to be moved, availability of resources and space are all factors to be considered. Heavy lifting equipment, for example, takes up a lot of space and requires a great deal more power than the small-scale demands of robotic laboratory or food-processing equipment. Each type of power has its advantages and disadvantages, according to circumstances.</p><h2>1. Strength</h2><p>Hydraulics is the best option for strength, because the liquid medium used for its operation has a high mass density and is largely incompressible. This means that hydraulics can develop much higher levels of pressure, and can use that pressure to transmit the power that will drive your application. Industrial applications using hydraulic power may command anything from 1,000-5,000 pounds per square inch (psi) of pressure, while some specialised applications such as mining equipment or heavy lifting cranes can develop 10,000 psi or more.</p><p>The fluids used in pneumatics have low mass density and are easily compressible. In some circumstances, gas or air can be compressed up to several hundred psi, but most mechanical applications are based on an operational pressure of only 80-100 psi. This means that pneumatic systems are largely incapable of the much larger force offered by hydraulics, and are unsuited to the moving or lifting of heavy loads. Compressed air is also subject to unexpected pressure drops or fluctuations which can cause operations to become jerky or unstable.</p><h2>2. Hygiene</h2><p>Pneumatic systems win out over hydraulics in the field of hygiene, as the only thing that can leak out of your system is air. Within the system itself, the compressed air will be cleaned of oil, water or metal particles, and any other contaminants, by the filtration unit. Pneumatic systems are generally favoured by environmentally-conscious companies or those contemplating greener manufacturing practices.</p><p>You'll also be likely to choose pneumatics if you're installing systems in a clean room, a pharmaceutical laboratory, or the food and beverage industry. In these environments there must be absolutely no risk of contamination, so hydraulic systems are generally off-limits as they may be susceptible to leakage.</p><p>Whether you choose water or oil in a hydraulic system, either of these may potentially leak out via faulty seals, valves or worn hoses. This will contaminate your clean environment despite any safeguards you may put in place. The presence of liquids may also invite corrosion of the hardware, with a further risk of introducing contaminants. Storage tanks are also required for the fluids, and residues must be disposed of at the end of the operational process.</p><h2>3. Speed</h2><p>Speed is one of the pneumatic system's biggest advantages. Compressed air has a high flow rate, which enables the quick release of energy and high-speed motion of moving parts such as actuators. Pneumatic actuators can achieve high cycle speeds and increased duty cycling, which deliver greater productivity. The advantage of rapid cylinder movement is further enhanced by the availability of equipment in very small sizes, ideal for use in applications where miniaturisation is a priority.</p><p>Air has a much lower mass density, and can flow much more quickly and easily through pipework. Another advantage of the pneumatic system is that valves and cylinders can quickly alter their state or change direction by dumping their compressed air. This can be voided straight to the atmosphere and requires no further disposal.</p><p>Water and hydraulic oil have a much greater resistance than air, with the viscosity of oil making it much slower. Although it will ultimately develop a greater degree of force and maintain constant pressure, it does not have the same rapidity as air movement, and may take longer to get your system running. In the event of a leakage or emergency, hydraulic fluid may not be vented rapidly to the environment, but must be re-routed back to its tank or reservoir.</p><h2>4. Energy</h2><p>Comparing hydraulics to pneumatics with regard to energy consumption, there are several factors to consider. Both systems usually require an input of electrical power to drive them, and a pneumatic system needs the continuous running of a compressor to provide the compressed air. The air supply cannot be recycled and requires constant replenishment, so energy consumption in this respect may be high. Any&nbsp;<a href="https://www.rowse.co.uk/blog/post/how-to-find-leaks-in-pneumatic-systems" target="_blank" title="How to Find Leaks In Pneumatic Systems">air leakage</a> will also waste energy in the system.</p><p>You also have to take into account the fact that pneumatic systems lose energy through heat produced by the compression process – though there are several measures that can be taken to make your system more energy-efficient. Fortunately, air is still free of charge, so there is no need to expend energy in obtaining, replenishing or disposing of waste products.</p><p>Hydraulic fluids can use the same oil or water over and over again after the initial start-up. Provided you have a good filtration system and keep it properly maintained, a hydraulic system can be very energy-efficient in the long run. However, electrical power is still generally required to drive the pump, and much of the energy consumed by the pump is wasted. This is because the fluid medium is in constant circulation to maintain system pressure, even though only short periods of actuation may be required to drive the application. The more viscous the fluid medium, the more energy will also be required to move it. However, significant improvements are being achieved, with technological advancements involving different types of pump and the potential of modulating drives.</p><h2>5. Safety</h2><p>Considering hydraulics and pneumatics in the industrial environment, pneumatics is undoubtedly the safer option. A leakage of compressed air is not going to cause contamination, since air is not poisonous or corrosive, although other gases used in stand-alone or portable equipment may be hazardous. Compressed air does not generally pose a risk of fire and it won't explode, but the forcible escape of air through mechanical failure may cause physical injury.</p><p>Hydraulic fluids, on the other hand, are always at risk of potentially dangerous leaks. Even water can cause damage if it's hot enough to scald. Other fluid media such as oil, ethylene glycol, plasma and fluid synthetics may be corrosive and/or poisonous. The fluid media may be combustible and require extra safety precautions, and used oil or fluids must eventually be drained and safely disposed of. In general, hydraulic systems incorporate fewer mechanical parts, but these may be subject to corrosion and potential component failures.</p><h2>6. Complexity</h2><p>Hydraulic systems typically have fewer moving parts and may be easily controlled with push buttons and simple levers. On the other hand, hydraulics rely on complex engineering that requires a system of valves and hoses, as well as a pump powered by an external energy source and a tank for storage of the liquid medium. It is possible to install a centralised power unit in a manufacturing plant in order to control several different hydraulic applications. Newer technology is introducing much better systems of managing speed, pressure and power.</p><p>Pneumatic system designs are also typically very simple, and operate at a much lower pressure, so their component parts may be made from cheaper and less complex materials. Since the fluid medium is not corrosive or combustible, precautions do not need to be built in against these safety hazards. Technological advances have increased the variety of uses for pneumatic systems, with miniaturisation and new materials helping to reduce weight as well as bulk.</p><h2>7. Maintenance</h2><p>Pneumatic systems are cleaner and easier to maintain than hydraulic ones, since the fluid medium is air. A regular schedule of inspection and preventive maintenance is usually all that's required to keep a pneumatic system running, e.g. checking the seals and making sure there is no leakage of air. The air does need to be cleaned of contaminants, and one of the most important maintenance procedures is the cleaning and regular replacement of the&nbsp;<a href="https://www.rowse.co.uk/blog/post/when-to-replace-pneumatic-filters" target="_blank" title="When To Replace Pneumatic Filters">filter-regulator-lubricator unit</a>.</p><p>With hydraulic systems, the main issue is corrosion. Unless you’re able to install pipes made of non-corrosive material, such as galvanised steel, regular monitoring will be required to assess how the pipes are being affected by the fluid medium. Water may cause oxidation, and oils or other media may leave deposits that will cause corrosion. Regular checks and replacements will be required for critical components such as seals, hoses and valves.</p><h2>Context is Everything</h2><p>The flexibility of air flow, and its precision in use, make pneumatics an obvious choice for such applications as medical tools, dental drills and small-scale robotics. Pneumatics are best employed in specialised environments where hygiene or green practices are paramount, but they are generally impractical for large-scale or heavy lifting duties. Hydraulics are ideal for such high-force applications, and are often found in construction or mining environments. They provide constant torque and force, in spite of any variations in speed, and maintain positional rigidity. At the end of the day, while technological advances continue to improve energy efficiency and performance on both sides, the hydraulic vs. pneumatics question ultimately boils down to context.</p>

Any type of modern construction or manufacturing application is probably going to incorporate one or all of three different kinds of power: electrical, hydraulic or pneumatic.

Hydraulics Vs Pneumatics

<p>Machine building has become more complex with the introduction of more automated systems, and designers must devote more careful attention to the newer safety standards that apply. Mechanical safety standards had to be supplemented with new procedures for functional safety and performance reliability. In 2006, <a href="https://www.rowse.co.uk/blog/post/iso-13849-performance-levels" target="_blank" title="ISO 13849">ISO 13849</a> was revised to incorporate safety functions for machine control systems, reflecting the move towards more software-based architecture.</p><p>Designers must anticipate every possible eventuality for the system, whether it is operational, not operating or being serviced. Incorporating standards like ISO 13849 will ensure the maximum possible safety of pneumatic circuits and components, based on risk assessment and performance level (PL) parameters. Using factors such as MTTFd (mean time to dangerous failure), CCF (common cause failures) and DC (diagnostic coverage), the PL can be calculated for each individual safety function, and a required level of performance stipulated (PLr).</p><h1>5 Key Safety Functions in a Pneumatic System</h1><p>When designing a pneumatic system, there are five key safety functions that must be considered.</p><ol><li>Protection against unplanned start-up</li><li>Exhausting</li><li>Holding, blocking and stopping</li><li>Reversing the movement</li><li>Reducing speed</li></ol><h2>1. Protection Against Unplanned Start-Up</h2><p>One of the most important safety functions in a pneumatic system, or indeed any automated system, is to protect against the machine starting up accidentally. The most common way to do this is with a pneumatic safety valve which has been built for the purpose, and certified to the appropriate PLr. For PLc a simple solenoid valve is sufficient, with a single valve element which will cut in. More sophisticated valve constructions are required for PLd or e applications, which will often need redundant valve elements to assure full safety functionality. Some products may have inbuilt electronics for this function, while others may require a safety PLC or external safe relay to comply with requirements for safety certification.</p><h2>2. Exhaust or Air Pressure Dump Protection</h2><p>Dumping or exhausting of air pressure will probably occur at the same time as an unexpected start-up, and many modern safety components combine the two functions. A pressure supply valve will shut off the air supply in the event of any failure, preventing excess air pressure building up in the system. At the same time, air pressure within the system will be dumped safely, although a manual exhaust release can also be installed as a back-up. In the two-channel, three-valve system that is commonly used with higher PL applications, the downstream flow will be greater than the input supply, so that downstream pressure can still be reduced to a safe level, even if the input valve fails to shut off. More recent technology is likely to incorporate soft-start valves and position sensors to control unexpected start-ups and pressure dumps.</p><h2>3. Holding, Blocking and Stopping</h2><p>Holding, blocking or stopping operational equipment is one of the key safety functions in a pneumatic system, and applies to all kinds of applications across a wide PL range. It may be as simple as installing a pressure-operated check valve in the cylinder port. The trapped air pressure in the cylinder will hold the load and make sure it can&#39;t move, and a pressure switch added to the circuit could provide DC.</p><p>In more complex applications requiring higher PL, a mechanical lock or brake may be installed on the cylinder&#39;s piston rod. This clamps the piston rod into position using spring pressure and an appropriate valve. Another version of the rod lock comprises a pneumatic device installed on the piston rod. This device only allows cylinder movement if air pressure is directed to a port on the rod lock itself. Increased DC can be obtained by adding a sensor to detect when the rod lock is engaged.</p><h2>4. Reversing Cylinder Movement</h2><p>In simple, low PL applications, this safety function can be accomplished in a pneumatic system by a spring-return solenoid valve. Higher PL applications will require a more robust solution, such as a servo-pneumatic unit. The safety functionality in category 4 control architecture relies on the position of each valve element being sensed and transmitted to a safety PLC. This will ensure that the cylinder may only extend if both valve elements have moved.</p><h2>5. Reducing Speed</h2><p>Reducing speed is the easiest to implement of the key safety functions in a pneumatic system. It requires the installation of simple flow controls that can be validated with the appropriate movement parameters. Tamper-resistant locks may be installed to ensure these parameters are not altered.</p><p>This post was originally posted on&nbsp;<a data-fr-linked="true" href="https://www.rowse.co.uk/blog/post/5-key-safety-functions-in-pneumatic-systems" rel="noopener noreferrer" target="_blank">www.rowse.co.uk</a>.</p>

Machine building has become more complex with the introduction of more automated systems, and designers must devote more careful attention to the newer safety standards that apply.

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