  Snake robots have been studied for decades with the aim of achieving
biological snakes' fluent locomotion. Yet, as of today, their locomotion
remains far from that of the biological snakes. Our recent study suggested that
snake locomotion utilizing partial ground contacts can be achieved with robots
by using body compliance and lengthwise-globally applied body tensions. In this
paper, we present the first hardware implementation of this locomotion
principle. Our snake robot comprises serial tendon-driven continuum sections
and is bent and twisted globally using tendons. We demonstrate how the tendons
are actuated to achieve the ground contacts for forward and backward locomotion
and sidewinding. The robot's capability to generate snake locomotion in various
directions and its steerability were validated in a series of indoor
experiments.
