Pneumatica

Pneumatica is a term that can refer to both an ancient treatise and the broader science of pneumatics. In historical contexts, it denotes the work Pneumatica, attributed to Hero of Alexandria, a first‑to‑early centuries CE engineer and writer. The text surveys devices and automata powered by air pressure, vacuum, and atmospheric phenomena, including automatic doors, fountains, and other experimental machines. It is among the earliest surviving systematic discussions of pneumatic devices and influenced later engineering and the development of automata in the Hellenistic and medieval worlds.

In a broader sense, pneumatics is the branch of physics and engineering that studies the behavior and uses of gases, especially air, as working fluids. It examines how gases respond to pressure, temperature, and flow, and how compressed air can be stored, controlled, and converted into mechanical work. Pneumatics is closely related to hydraulics, but it relies on compressible gases rather than incompressible liquids, which leads to different characteristics such as rapid response and energy storage in tanks and lines.

Modern pneumatics encompasses a wide range of practical applications. Systems use compressors, reservoirs, valves, and actuators to power tools, automation equipment, braking systems, and industrial robots. Advantages include simplicity, clean operation in hazardous environments, and high speed of actuation; limitations can involve energy efficiency and force at small diameters. The term remains central to industrial automation, tooling, and process control, linking ancient theories to contemporary engineering practice.