Dynamic BO bonds-induced viscoelasticity and surface adhesion regulation for constructing konjac glucomannan-based soft actuators with superior mobility and capturability.

In all soft actuators, achieving both outstanding mobility and capturability is crucial; however, these properties are usually mutually exclusive due to the lack of an effective mechanism for controlling the viscoelasticity of the switching polymer matrix while maintaining a moderate surface adhesion. In this study, we propose a dynamic bond cross-linking strategy to successfully develop a magnetically responsive soft hydrogel (MRSH) with exceptional mobility (117.56 mm/s) and capturability. By introducing dynamic BO bonds into the KGM@FeO@PSSMA NPs composite matrix, the crosslinking density and overall cohesion of MRSH can be precisely controlled, resulting in unique non-Newtonian fluid characteristics. Additionally, the dynamic BO bonds transition between associative and dissociative states with the hydroxyl groups on the KGM molecular chains, which can effectively regulate the amount of hydroxyl groups on the surface of MRSH, thereby achieving demonstrate moderate surface adhesion. As a result, the synthesized MRSH exhibits remarkable capturability on various target surfaces and maintains outstanding mobility, even in underwater environments. This work paves the way for new possibilities in the field of soft actuators and engineering by overcoming the limitations of traditional soft actuators in terms of surface adhesion and responsiveness through innovative structural design and material combinations.