Well, being the manipulator removable, so you can attach other thing to the valve shaft, you have so much options.
You could use a coupled rotary actuator to the shaft by the means of a shaft coupler. There's many types, this is a simple one, but you probably would not get the actuator axle full aligned with the valve shaft, so a coupler ...
Whether a single 3-way, 2-position pneumatic valve (typically with a work port, an input port, and an exhaust port ‒ see page 3 of nationalpneumatic.com's pdf about valves) will suffice depends on information not given in the question. For example, if you can turn the compressor on or off at will, and if it will hold pressure when off, you can attach the ...
Generally you won't need a servo. The more common way to throttle a flow is to use pneumatic solenoid valves (which are either open or closed) and control them with PWM.
See (for example) this link. This is also how the boost controller in many cars works.
The problem with vacuum pick and place systems is the amount of time it takes to create the vacuum, so your design will revolve around your requirements.
If you run the vacuum continuously then, as you approach your target, you only have to wait long enough for the channels on your pick-up head to evacuate.
If you switch off the vacuum pump, air ...
It is pretty common to take a simple and cheap solenoid valve and use a PWM at the input
TI has a pretty nice driver (DRV102) which uses a analog input and provides enough power to switch the most valves. I don't even need a MCU, just a variable resistor is enought
Then just take a cheap valve and the job is done
If the valve has enough traction with a rubber band1, you can use one to control the valve as in the image below.
To make sure the rubber band doesn't start falling over time due to gravity, you could attach a half-circular plate under the valve, so the rubber band wouldn't slowly slide down as it would rest on that plate. Note that the amount of the ...