proportional weight paint deformation I am trying to deform a flat coil for an animation:



The bone rotates around its own axis (z) and the coil-mesh should rotate and get closer to the bone depending on the distance to the center. So basically the "density" should be increased in the process.

My first thought was using weighted painting in radial fashion. Unfortunately this didn't work at all.

My second thought was using shape keys or key framing. Before I try that I wanted to ask if weighted painting is the way to go and not a dead end.

Edit: Trying atomicbezierslinger's answer results into this mess (probably my fault):
Consider a Curve Deform modifier.





The curve modifier is applied to a long strip with high density as in the original question.  Plane scaled  into a strip.  Plane moved along the X axis in the example below.  The bone is not used in the images below.


Create a Spiral Curve manually or use the add on  Add Curve Extra Objects.
The dense vertex strip will be moved in the X direction to travel along the spiral.
Consider scaling in two dimensions the spiral. Scale Not Z axis.
The curve modifier is specified along the X axis in this example.  So scaling the strip along the X axis is easy and provides a movement.




Image above shows a shape key created with a proportional edit smooth from center of spiral

Lastly


Consider scaling the bone, not recommended, and a one minute experiment might be interesting.