Atoms supports blend shapes deformation. In order to use blend shapes during the simulation the blend shapes target must be exported using the export mesh tool. The export mesh tool writes the P, N, id and name information of each target inside the mesh file. The variation builder automatically exports the blend shapes information, so if you created your variation with the variation builder you have already all set up.
When you load a mesh inside the variation manager atoms load also all the blend shape targets if they exists. In order to control the weight of each blend shapes some special metadata are used.
These metadata should have this format: (AGENT TYPE NAME)_(MESH_NAME)_(TARGET_ID)
So for example if you added some blend shapes to the atoms robot head, you can activate with the double metadata "atomsRobot_Head_0","atomsRobot_Head_1", "atomsRobot_Head_0" etc. Please remember that the geometry name is not the mesh file name, but the name used inside the Variation manager.
You can add these metadatas usign the "addMetadata" behaviour or you can animate the blend shapes using the blendShapeAnim module, please have a look at the tutorial section.