Smooth Vertical Surface Climbing With Directional Adhesion

Abstract

Stickybot is a bioinspired robot that climbs smooth vertical surfaces such as glass, plastic, and ceramic tile at 4 cm/s. The robot employs several design principles adapted from the gecko including a hierarchy of compliant structures, directional adhesion, and control of tangential contact forces to achieve control of adhesion. We describe the design and fabrication methods used to create underactuated, multimaterial structures that conform to surfaces over a range of length scales from centimeters to micrometers. At the finest scale, the undersides of Stickybot's toes are covered with arrays of small, angled polymer stalks. Like the directional adhesive structures used by geckos, they readily adhere when pulled tangentially from the tips of the toes toward the ankles; when pulled in the opposite direction, they release. Working in combination with the compliant structures and directional adhesion is a force control strategy that balances forces among the feet and promotes smooth attachment and detachment of the toes.

Improving controllable adhesion on both rough and smooth surfaces with a hybrid electrostatic/gecko-like adhesive

“…The performance of various tip shapes was characterized in previous work [34], showing that the mushroom shape enhances adhesion by several fold over a flat tip shape. Finally, anisotropic microstructures use the directional preference of the adhesive's shape, similar to the structures on a gecko toe, to turn adhesion on and off easily [35][36][37].…”

Rectangle-capped and tilted micropillar array for enhanced anisotropic anti-shearing in biomimetic adhesion

“…When loaded in forward direction, gecko's adhesive toe pads stick with a strong force to the surface, however, they can also be easily peeled off from the surface when loaded in the reverse direction [6]. This directional or anisotropic adhesive behaviour that allows smart or controllable surface attachment and detachment has inspired many applications such as climbing robots [7], clean transportation systems [8,9] and micro-transfer printing mechanisms [10]. Rapid switching of the gecko's toe pads between attachment and detachment can be attributed to millions of inclined seta shafts and to the corresponding loading response of the toes of the gecko [11][12][13][14][15].…”

Development of a Multi-functional Soft Robot (SNUMAX) and Performance in RoboSoft Grand Challenge

“…The shape of the claw is suitable for capturing small objects (Figure 7A), but not for big ones (Figure 7B), and the claw does not create enough friction to hold an object of any significant weight. Therefore, a polymer pad with spines, inspired by the Gecko pad (Kim et al, 2008), was added to the claw, as shown in Figure 7D. The polymer pads were molded from a laser-cut acrylic plate.…”