Visualization shows the microgel network architecture in fibrin–microgel composite materials. Confocal microscopy images of fluorescently labeled microgels (shown in blue and red) and fibrin (shown in green) demonstrate that at a critical volume fraction, the microgels form an interconnected tunnel network within the fibrous fibrin matrix. Microgels are tightly packed and only slightly jiggle around within the microgel domains. (Credit: Alison Douglas)
