Bending Linked Meshes (Phototropism)

Hi Everyone,

I am trying to replicate the mechanical act a plant goes through when leaning towards the sun (although on a very simplistic level).

For the very first step I am attempting to bend two linked meshes using springs in kangaroo. Their rest lengths are set currently but will later be linked to irradiation levels using geco.

I can get both meshes to contract as a set of springs however I cannot connect them to each other to work in tandem, I get an exception error from kangaroo every time I try to add the connections as a rigid spring.

The hope is that if one mesh contracts more than the other, the joined system will bend with one mesh shortening and the other lengthening.

I have read a few posts on bending but couldn't get the definitions to work and may have just missed something. Do I need forces other than springs to implement bending in the mesh, is it possible to create a bend in a paired system using only differing levels of contraction?

The latest definition I have tried adds a bending force between all the points of the mesh. I may have misunderstood how to use this force so please tell me if I am doing something simple wrong or if there is a discussion I may have missed where I can look into the problems I am having.

Any help anyone can give or any people working on something similar would be greatly appreciated.

Mike