Mimicking growth of axons in neuronal networks by photocatalytic gold growth on nanooptical templates

In neuronal networks, the capability of dynamic stimulus-controlled formation and dissolution of network connections is an important factor for efficiency. In biological neural networks, fast-reacting local synaptic network connections are combined with the slower and long-range growth of global axon connections. Connections are formed in an interplay of self-organized, parallel connections and genetically predetermined self-similar blueprints. Here, we aim to mimic the growth of axons by photocatalytic metal line formation from solutions. Nanooptical template substrates serve as two-dimensional technical network blueprints. Near-field optics is employed to locally focus incident plane-wave light. Titanium dioxide (TiO2) is used as the guiding layer because of its high refractive index and its well-known photocatalytic properties. A nanograting is fabricated on a glass substrate via nanoimprint lithography followed by RF sputtered TiO2. The photocatalytic gold growth from solution is investigated experimentally. Accompanying simulations are implemented to analyse the influence of material, geometric and illumination properties.