Temporal and spatial programming in soft composite hydrogel objects

Abstract

Soft composite hydrogel objects formed from the biopolymer sodium alginate, the enzyme urease, and oil droplets are formed by a simple gelation procedure to produce autonomous bodies with both time and spatial programming. These continuous objects of non-uniform dimensional composition selectively respond to an environmental stimulus of urea and change colour or disintegrate at pre-defined locations within the hydrogel structure after pre-set time intervals. The spatial and temporal responses of these hydrogels to an environmental stimulus are valuable tools in areas such as soft robotics.