Unlike Robotnik he doesn't have lots of power or money so instead of living in official residence in Mobius he lives in a cave... under Robotnik's residence.
Von Schlemmer went to the same university with Robotnik Sr. but he was very dumb compared to him. When Robotnik Sr. collided Mobius with Earth he suddenly fell of the planet and landed on The German Prison and destroyed it. Robotnik Sr. and Indiana Jones will renovate it later.
Von Schlemmer invented some stuff but they weren't useful at all. The only invention somebody found useful was a gigantic computer that allowed a player to play Cd-i shames without controller. Professor later sold it to Nintendo. Shigeru Miyamoto completely rebuilt that computer to fit on TV and released it as Nintendo Kinect. Only 0.001% of Nintendo Kinect is Von Schlemmer's technology, so Nintendo didn't pay him any money.