A soft climbing robot based on smart wood with switchable adhesion

Climbing robots have vital uses in uncharted terrain exploration, military intelligence collecting, and other areas. To address the drawbacks of classic wall-climbing robots, this study introduced a novel soft climbing robot constructed of the smart wood with switchable adhesion force. The experimental findings indicated that the soft robot implemented in this research could effectively perform climbing movements on diverse walls and sloping pavements, enabled by temperature control through cold/hot water circulation and pneumatic actuation. Further research revealed that the reversible phase transition of PNIPAM at different temperatures was the main reason for the variable adhesion force of the smart wood. Moreover, the adhesion force model developed in this work indicated that the adhesion force of the smart wood surface was mostly composed of the contact mechanics force and the capillary force. Finally, this study will offer novel insights for the design of climbing robots and advance their potential applications.