What is the difference between mechatronics and robotics, if any?

Mechatronics is a reaction to the fact that one can not design good next gen products without knowing both the electronical and mechanical realms. Having kickass electronics can not overcome a bad mechanical design. Conversely a badly done electrical system can not control the mechanical part so that you gain benefits over traditional mechanical engineering. This is not to say you can not have specialists, but the overal design needs people with a broader view.

There are two or possibly three schools of mechatronics engineers. Some are electrical engineers, and some are mechanical enginers or possibly control enginers. So the fact that somebody is a mechatronics engineer tells quite little of what their education entails.

Now robotics is quite clearly a subfield of mechatronics because mechatronics includes all kinds of things that arent entirely robotic in nature. Things like active vibration damping, electroactuated hydraulics, and many industrial automation things fall into this category.

So Robotics is just more specific moniker. Its still not very specific but more specific.