Continuous electro-growth of hierarchically structured hydrogel on non-conductive surface

To design hydrogels with hierarchically ordered structure is of significance for biomimetic applications through simulating natural biological soft tissues. Due to the soft and fragile features of the hydrogel, it is challenging to create complex structure with modulated orientation in a facile and continuous way. In this study, we developed a novel method to electro-assemble natural polymeric hydrogels on non-conductive surface, which eliminating harsh pH change near the electrode during electrodeposition. Under optimal circumstances, charged polymeric chains packed densely in a continuous manner and aligned parallelly to the non-conductive surface. The oriented hydrogels can be peeled off from the non-conductive surface and demonstrate excellent mechanical property. We also found electric field intensity had a profound effect on the microstructure of the hydrogel. By programming the electric signals, we can construct complex structured hydrogels with regulated orientation, which should have potential applications in biomimetic material design.