I'm trying to build a 3d part which resembles a thin membrane with an approximate elliptical surface (xy plane) and with varying thickness in the z direction. The membrane dimensions are approx 1.5mm x 2.5mm for the minor and major axis of the surface and the thickness varies from 1um to about 20um. I am using an imported image of a contour map and have tried tracing around the edge with a spline, extruding this over a very small thickness and then using freeform to place control curve lines across the membrane surface, place control points and adjust each of them to the required height in the z direction. I have encountered a few problems mainly I think because of the disparity in dimensions and very thin adjustments using the freeform tool.
I suppose all I'm looking for is some advice on whether I'm going about this the right way. I'm considering scaling up the variation in the z-direction initially (can rescale it later via separate modelling software) and using the same technique.
However I'm wondering if anyone has made a similar structure before or has better ideas of how to go about this.
Any help is most welcome.
Thank you in advance