Question on transducer excursion

You've probably seen my post on madisound too and people are surprised. Anyway here are the details.
I am a student currently pursuing EE and CE (Electrical and Computer) at the University of California.
I am currently researching under a professor who is doing groundbreaking research and is a pretty respectable figure in MEMS and nano-systems not mentioning a host of noteworthy patents under his hat.
He knows of my love for audio and has come up with an old and rejected idea that he has great faith in. He believes you can control the excursion of an actuator (actuator=something that can move in a controlled manner.)
if you connect an arm to a voice-coil based transducer.
He says this because he has great faith in the fact that one of the people who was instrumental in devising a sub atomic microscope, used voice coil acuators to move sub-micron distances.
Since it is an exploratory undergrad project. basically i would like to know how we can get a controlled excursion with a voice coil if we supply a pure (cleaned) DC
Is the distance a linear function?
Is there a mappable function?
since smallest possible actuation is preffered. Would it be better to use an ESL instead of an EDL?
Does an ESL excurt without vibrating?(Oscillation is not desirable!)
Which transducers shown minimal excursion?
Do HDCD's or piezo electric horns have any displacement at all?
Interesting issues... an arm connected to a voice coil based transducer sounds alot like the definition of a phonograph playback system. Vinyl aside, I'd say that from rest the excursion distance is non-linear with applied energy. Designers seem to seek actuators which are stiff yet compliant, that is stiff enough not to overreact but compliant enough to react with some desired efficiency. Consider both the elasticity of the actuator's suspension and that of the actuator material itself. From rest, moving an actuator against these built in resistances twice as far than its smallest possible actuation (SPA) may take more than twice as much energy. However given that moving more than one SPA will take additional time, this converts the model from a static to a dynamic one. Some actuators may become more compliant once in motion. But overall, given that the power source will apply energy in waves, your solution may be in finding how many waves of what size (two more variables) will be necessary to overcome inertia and prompt a given actuator from rest but no further. Are two tall skinny waves as good as one short fat one? Different actuators will react differently to the same stimulus. In any case, your results will be discernable to the degree the measurement instruments can detect the energy applied and the resulting movement.

Nice project. At first select a popular or classic actuator. Perfect your technique. Then select a handful of others. Write an article. Design an analyser. Sell either one or both to Stereophile. Best of luck.