For the first time, our interdisciplinary approach interconnects three solid research lines carried out at our respective laboratories in Mainz, Trento, and Glasgow. First we will develop micropatterned photosensitive hydrogels capable of complex reversible changes in their physical and chemical properties when subject to light patterns. Next, we will use the mm-size bulk hydrogel unit to implement large-scale optical networks with synaptic plasticity, where the local connectivity preserves memory of the past optical inputs. In parallel but with a more applied mindset, we will develop photonic devices with enhanced functionalities provided by the hybrid microscale integration with hydrogels for future scalable photonic neural networks. Finally, we will explore chemical information transfer mechanisms in hydrogels based on uncaging chemicals upon light irradiation, with the objective to understand and exploit the complex spatiotemporal dynamics in hydrogels for future multisensory applications.