A selectively rigidizable and actively steerable device is described. In one aspect, an articulatable device is described that includes a flexible inner tube having a first lumen, a flexible outer tube that receives the inner tube, and a multiplicity of overlapping, rigidizable scale-like strips. Each scale-like strip is coupled with the inner tube and positioned between the inner and outer tubes. Of particular note, the overlapping strips are actuatable between a non-rigidized state in which overlapping strips are slideable relative to one another and a rigidized state in which overlapping strips are not slideable relative to one another.