PiezoClimber: Versatile and Self-Transitional Climbing Soft Robot with Bioinspired Highly Directional Footpads

The ability to climb is crucial for terrestrial robots to expand their scope of application with improved navigation capacity. While some soft climbing devices are available, they often lack versatility when it comes to adapting to rough surfaces and changes in terrains. In this regard, a piezo-based soft robot with bioinspired footpads has been developed that can deliver superior climbing performance. Through their unprecedented directional friction, these footpads enable the robot to complete rigorous climbing tasks on surfaces with a climbing angle of 0-180 degrees and a variety of roughness from ultra-smooth to millimeter-scale. With a unique slide-swing gait, the robot is able to complete fast climbing on a 90 degrees substrate at a speed of 1.4 body lengths per second (BL/s) and self-transitional climbing on surfaces with a roughness difference of 11 mu m and an angle change of 60 degrees in 5 s without active control. A scaled down version of this climber is also presented with increased mobility to traverse steps of 3 body heights and slits of 0.75 BH effectively. In summary, the development of this soft robot with highly directional footpads paves the way for soft robots to navigate varied surfaces and ascend challenging terrains with improved mobility. Soft climbing robots are developed based on a piezoelectric actuator and two bioinspired footpads with directional friction. The robots demonstrate versatile climbing on both smooth surfaces and rough surfaces. With intrinsic flexibility and efficient locomotion, the robots are demonstrated to deliver a cargo on transitional terrains. Scaled piezo-based robots are also demonstrated with increased traversal ability on inclined complex terrains.image