Controlled Cooperative Wetting Enabled Heterogeneous Structured 3D Morphing Transducers

A unique microfluidics approach for functional hydrogel patterning with multilayered heterogeneous structures is presented. Prepolymer solution droplets with differentiated sodium acrylate concentrations are dispensed/printed in a wetting‐controlled “two‐parallel plate” (TPP, like a Hele‐Shaw Cell) system. The gelation within the system enables hydrogel bilayer structures with reconfigurable 3D deformations driven by in‐plane and through‐thickness heterogeneity under stimuli‐responsive mask‐less swelling/deswelling. The cooperation between swelling mismatch of functional groups results in a higher complexity of 3D reconfiguration in responding to discrete levels of stimulation inputs. This facile patterning technology with an in‐built ionic hierarchy can be scaled up/down with advanced transducing functionalities in various fields. Reconfigurable soft structure 3D morphing is enabled by the cooperation between swelling mismatch of functional groups patterned as heterogeneous hydrogel bilayers. Multiple deformation states can be driven by in‐plane and through‐thickness gradient during external stimulation such as ionic concentration change. The fabrication process is enabled by wetting‐controlled, surfaces‐empowered open‐microfluidics in a “two‐parallel plate” (Hele‐Shaw Cell) system.