From 1D to 3D: a new route to fabricate tridimensional structures via photo-generation of silver networks

A rapid and cost effective method has been developed to fabricate 3 dimensional (3D) ordered structures by photo-generating silver networks inside a 1D layered heterogeneous laminate composed of poly(vinyl alcohol) (PVA) and poly(methyl methacrylate) (PMMA). By designing the photo-mask meticulously, the silver nanoparticles (NPs) produced by UV light aggregate to form frameworks in different forms, which perform as the anisotropic component, i.e. the building blocks, thus converting the 1D structure into 3D. Formation of silver NPs increases the refractive index (RI) of the PVA layers, thus bringing optical change to the 1D laminar structure, which allows us to trace the silver formation process by measuring the change of RI value and reflectance spectra. The 1D layered structure is a good building matrix for 3D construction because the total number of layers and the layer thickness can be finely tuned flexibly which allow us to further study the various properties caused by the structural modulation. By utilizing photo-reactive silver ions, an innovative strategy of fabricating 3D structures through in situ photo-generating silver building blocks inside the laminar matrix is established, which makes it possible to fabricate 3D micro/nano composite materials with potential applications in fields such as sensors and photonic meta-materials.