2024-03-16

Moisture actuated cobalt alginate discoloration artiffcial muscle

Abstract:Artiffcial muscles have the ability to sense changes in the external environment and generate rapid and significantcontraction deformation or rotational motion. However, most artiffcial muscles are limited to a single form of deformation, and there are still great difffculties in achieving complex dual response modes. Herein, a novel artiffcial muscle made of cobalt alginate ffber with both rotational/contraction deformation and discoloration functions was successfully prepared by a simple wet spinning and directional twisting methods. The wet-sensitive color change performance is achieved by the formation of differ

ent hydrates of cobalt ions in varying humidity conditions, while rotational motion is induced by radial

untwisting resulting from ffber swelling upon moisture absorption. In addition, the artiffcial muscle ffber exhibited a transition from blue to purple to red as the environmental humidity changes from 35 % to 85 %. When the ffbers were exposed to water, the twisted ffber with a twist count of 2500 truns provided a rotational speed of over 2000 rpm, and the actuating and discoloration performance did not signiffcantly decrease in 50 repeated cycle tests. This stable shape and color dual response artiffcial muscle can simulate traditional windmill devices, while also providing a new design idea for smart textiles and humidity visualization devices.

Xiang C, Wang W, Wang H M, et al. Moisture actuated cobalt alginate discoloration artificial muscle[J]. Chemical Engineering Journal, 2024, 487: 150520.