Bio-inspired Adhesion Device for Fixation, Walking, and Exercise in Microgravity Environment

With the development of human spaceflight, the impact of the microgravity environment in space stations on the work and life of astronauts has received increasing attention. For astronauts, establishing stable and switchable attachments to multiple surfaces in an orbiting space station is important and yet a great challenge. Here, inspired by the variable stiffness structures of biological adhesion organs with different functional directions, a multi-modulus adhesive unit is designed. The low-modulus adhesive layer provides good adaptability by mimicking the soft bottom of the rock-climbing loach suction cups and the setae on the gecko’s toes; the high-modulus flat substrate provides good stiffness to suppress deformation; the elasticity adaption layer reduces preload required for attachment to uneven surfaces like gecko muscular tissues, and the detachment switch made from nylon rope allows switching the adhesion force by adjusting the angle of force. Experiments in simulated microgravity environments demonstrate the ability of the adhesive shoes to rapidly generate strong and switchable adhesion and friction on rough surfaces, and tests in China's space station show that adhesive shoes based on multi-mechanism adhesion are a viable option for lower limb muscle exercising.