A roboticist or robotics scientist was someone who experimented and studied the field of robotics.
According to Geordi La Forge, Doctor Noonien Soong was Earth's foremost robotics scientist. (TNG: "Datalore")
Follow its defeat on Molmol's homeworld, the evil computer AGIMUS was transported to the Daystrom Institute where it was studied by the Institute's roboticists. (LD: "Where Pleasant Fountains Lie")