Pneumatics (pronounced new-MATT-ix) is an aspect of physics and engineering that is concerned with using the energy in compressed gas to make something move or work. The origins of pneumatics trace back to the first century when the Greek mathematician Hero of Alexandria created mechanical systems powered by wind and steam and documented his processes. Today, pneumatics plays an important role in manufacturing and mechatronics.
With pneumatics, valves control the flow of energy from pressurized gas, which is often simply compressed air. The device that converts energy from the pressurized gas into motion is called a pneumatic actuator. Pneumatic actuators are often powered by electric compressors and are capable of producing either linear or rotary motion. A nail gun is an example of a linear pneumatic actuator. When the user pulls the nail gun's trigger, a valve opens and compressed air is released with enough force to drive the nail into a solid surface. In manufacturing, pneumatic technology and automated solenoid valves can be used in an assembly line to move, process and package product.
Pneumatic systems are similar to hydraulics in function, but hydraulic systems use liquid to power movement and work instead of gas. Pneumatic systems are simpler to design and simpler to manage than hydraulic systems, but hydraulic systems are capable of greater pressures: up to 10,000 PSI (pounds per square inch) with hydraulics, compared to about 100 PSI with pneumatics. In general pneumatic systems are more sustainable than hydraulic systems because air can be exhausted into the atmosphere, while hydraulic fluid must be exhausted into a fluid reservoir and eventually disposed of.