A robotic actuator includes an internal anchor and an instrument. The internal anchor is adapted to be inserted into a body via an entrance port, positioned inside the body, and magnetically coupled with an external anchor positioned outside the body. The instrument is adapted to be inserted into the body via the entrance port and secured to the internal anchor. The instrument includes an end-effector having multiple degrees of movement via multiple axes, and a plurality of actuators that provide the multiple degrees of movement.