The COMSOL Multiphysics software is not limited to the common couplings described in this chapter — there are many other phenomena that can be easily modeled in microfluidics. In many cases, physics interfaces can be coupled simply by entering expressions from one physics interface (such as the local temperature) into fields in another physics interface (for example in the Model Inputs section of a Fluid Properties node). Additionally, COMSOL Multiphysics includes powerful coupling operators that enable physics interfaces to be linked by projections, extrusions, or scalar quantities such as integrals and global averages.