Cellulose-based hydrogels are considered promising candidates for modern engineering applications in soft robotics and as building blocks for 4D programmable materials. Their ability to serve as mechanical actuators in aqueous environments and respond to external stimuli has been widely demonstrated. However, the precise tuning of their mechanical properties, a prerequisite for their integration into functional devices, still remains an open challenge.
This project, as part of the Exzellenzcluster BlueMat – Water-Driven Materials, focuses on the realization of mechanical actuation in hybrid hydrogel systems consisting of two matrices: a soft cellulose-based matrix and a hard nanoporous gold matrix. The first challenges to be addressed are the control of hydrogel–wall interactions during hybrid formation and the exploration of their responsive behavior. Additionally, the fabrication of state-switchable cellulose hydrogels via reversible Zn²⁺/Ca²⁺ cation exchange will be investigated, accompanied by molecular dynamics (MD) simulations and thermodynamic modelling. Finally, an alternative biotechnological approach for the fabrication of hybrid hydrogels and the optimization of their mechanical properties will be examined. This approach involves the direct bacterial growth of cellulose on the nanopores of the gold matrix, with a view to also rendering the hydrogel state-switchable in response to enzymatic reactions.
All in all, this project combines existing knowledge of cellulose-based hydrogels, the ambitious prospect of reversible hydrogel state tuning, and genetic engineering approaches. This endeavor supports the overall vision of Research Area A of BlueMat, namely the use of water as a working fluid for the conception of innovative materials with sensing, actuating, and switchable acoustic transmission capabilities.
