wel.. industrially, usually three types of actuation forces are used...electro-magnetic (motors) , pneumatic (air) , hydraulic (oil).
the thing about hydraulics and pneumatics is that they are costly. and like motors, you need to keep in mind the design parameters of your project in order to use them properly. Hydraulic and pneumatic pressure is used via piston-cylinder arrangement (usually).
select a cylinder diameter.
since Force = pressure * area. determine the maximum load (load=force) your cylinder needs to bear (both axially and vertically, if the load is not entirely vertical), add factor of safety , and you have your operating pressure.
(usually, the load and operating pressure is known[determined by pump output] , and a suitable area is selected)
with hydraulic and pneumatic systems, you also need a reservoir/accumulator that would supply pressure so that:
-pump/compressor won't run continuously
-to meet transient load demands
-to make the piston reach a safe point in case of power failure. etc
lastly, you would need control valves to control the direction and flow of the fluid , and hence the cylinder.
That's about as simple as i can put it.There are more things, but the above are the most basic. try google for more info, i'm sure you can find much more.
