pH-induced synergistic changes in color and shape of soft actuator based on degradable carbon dots/sodium alginate gel

Carbohydr Polym. 2025 Mar 1:351:123112. doi: 10.1016/j.carbpol.2024.123112. Epub 2024 Dec 6.

Abstract

Soft actuators for intelligent robots require further elaboration to improve their biomedical applicability, which has led to the development of a series of flexible stimulus-responsive materials. However, fabricating degradable soft actuators that exhibit synergistic color and shape changes in response to environmental stimuli remains challenging. Here, we developed a soft actuating gel based on carbon dots (CDs) that are chemically cross-linked with sodium alginate. The soft actuating gel exhibits rapid synergistic changes in color and shape in response to pH owing to CDs protonation and deprotonation. Soft actuators constructed using the gel and poly (lactic acid) tape not only perform actions, such as grasping and lifting, but also camouflage and warn through self-color changes. The combination of pH-responsive CDs and degradable polymers provides a simple strategy for fabricating degradable soft actuators that exhibit synergistic changes in color and shape, and is expected to promote further research into soft actuators.

Keywords: Carbon dots; Color-change; Degradable; Sodium alginate; Soft actuator; pH-responsive.