Abstract: A surgical system includes a steerable instrument. The steerable instrument includes a first tube including a first serpentine beam formed in a tubular sidewall thereof, and a second tube including a second serpentine beam formed in a tubular sidewall thereof. The first and second tubes are concentrically nested and positioned so that the first and second serpentine beams are at least partially aligned with each other axially and face in radial directions that differ angularly from one another. The first and second tubes are connected to each other distally of the first and second serpentine beams. The first and second serpentine beams define a bending segment that is actuatable to form a bend in the nested tube structure in response to differential axial forces applied to the first and second tubes.