fig6

Figure 6. Characterization of the performance of LRH microvalves. (A) Schematic diagram of duality color-changing unit assembly. (B) Hydrogel microvalve in the closed state; from left to right are the side view, A-A cross-sectional view and the actual top view. (C) Hydrogel microvalve in the open state; from left to right are the side view, A’-A’ cross-section Schematic diagram and physical top view. (D) Color change process of photonic crystal layer on the surface of the duality color-changing unit after hydrogel microvalve is opened (dotted line indicates the position of the flow channel under the film, the green area is the initial color of the photonic crystal film and the red area indicates that the film is wetted by water). LRH: Light-responsive hydrogel.