Hi,
Here is what I’m looking for :
I need to bend a surface with an animation.
Here is what I do :
Under 3D STUDIO, I use “bend” modificator to animate my surface, but UNITY dont import the animation. 
Under 3D STUDIO, I animate the surface vertices but UNITY dont import the animation.
How can I solve my problem ? 
Many thanks for your help !
My usual qualifier… I am a Unity Noob…
However, it is not surprising to me that mesh deform techniques do not export from Blender, anyhow, we do know that Bone exports do work. So lose the mesh deform animation, and replace it with a bone deform, then import that animation, and you should be gold.
As a super bonus side benefit, you will start learning the very beginnings of character animation, and once you see how bone deforms work, I bet you do your first character animation (well at least rigging) within a week or so.
If you need the techniques on how all this works, the blender website has several character animation videos, and it would be worth while for you to work through one of those tutorials, as it will greatly increase your knowledge about Blender works, and about how character animation works, and you will make better games as a result.
For what I know bones are the only supported type of animation deformer supported by Unity, just read the manual!
You will need to write your own bend system in Unity, it isnt that hard to do, Ive done it as seen in the video below, there is also another chap working on a script that will export all kinds of vertex animations from max to unity which is like my system but mine will give realtime control over all the modifiers.
To megmaltese : Do you know where I can find a good tutorial to use bones under 3D STUDIO ?
To SpookyCat : Really good job !! Is there a way to use your script ? I don’t need to use realtime control, just an animation.