From a pure math standpoint, get really familiar with your trigonometry (angles, sines, cosines) and how to do problems with really big matrices. At some point in robotics you will have to be able to do the math to find the position of the end of the robot arm. This involves A LOT of equations, and the easiest way to deal with this many equations is to put them into matrix form. It makes it easier not only to do by hand, but also to program into the robot controller.

From the science end you will want to learn at least the basics of electromagnetism. When you build robots you will have power wires running to the motors of the robot, as well as signal wires going to the sensors to read the robot’s position. If these wires are not run properly electromagnetic interference will screw up your sensors.

I assumed you were looking for general things to look out for in the future of your education, the above should be a good start.