Material property assignment with Current Expression

Hi all,
I've got a question this time concerning the assignment of Material Properties using the Expression Editor.
I have a property (thermal conductivity of the solid phase) which changes depending on the temperature of the solid. Given that the temperature of the solid changes during the simulation, I also want its thermal conductivity to change, following the temperature variation. Therefore I assign an equation (with the Expression Editor) to the thermal conductivity where the unknown is Temperature. However there is no change during the simulation and the value of thermal conductivity stays equal to its initial condition.
Does this mean that it is impossible to assign varying Material Properties using equations linking them to Process Variables?
Thank you in advance for any help!

Hi Zeno, you are correct in that the expression editor cannot be used to define variable material properties during a simulation. To do this you would need to develop an IFM plugin.

All material properties related with sources/sinks (e.g. in/outflow on top/bottom, source/sinks for fluid, heat and mass) may be manipulated by parameter expressions. If you want modify other parameters you need to develop your own plugin as already stated by Blair.