In exemplary implementations, a target rod is actuated. The target rod is part of a set of threaded, elongated rods, the longitudinal axes of which are substantially parallel to each other. The set of rods has an interior region and a perimeter region. Actuators induce vibrations in a set of perimeter rods. These vibrations are substantially perpendicular to the longitudinal axes. Furthermore, the vibrations are transmitted to interior rods, causing a target rod in the interior region to rotate about, and translate along, the longitudinal axis of the target rod. The target rod undergoes stick-slip motion relative to adjacent rods.