Novel soilless cultivation techniques are required to provide a solution to the growing food demand. The increase in land desertification coupled to climate change is an opportunity to develop efficient and superior soilless substrates.
Hydrogels are suitable materials for plant growth due to their unique tunable transport properties, capability of holding large amounts of water and high degree of biocompatibility. Thanks to these properties, hydrogels have been used in a variety of of biomedical and engineering applications, ranging from drug delivery to wastewater treatment and soft robotics. In particular, it has also been shown that the use of additive manufacturing can be used to fabricate hydrogels with user-defined architectures and controllable biological functions. This thesis aims to develop a phytocompatible hydrogel suitable for additive manufacturing to mimic soil features and properties. This could be achieved via the development of techniques by which self-supporting hydrogels with complex designs ranging from μm to cm can be obtained. Material extrusion and vat polymerisation 3D printing processes are investigated depending upon the type of material, the conditions required for printing and the desired final resolution. However, the development of printable formulations which are phytocompatible is not widely explored in the literature. This thesis describes the development of novel phytocompatible formulations which can be used for both material extrusion and vat polymerisation processes. In addition, due to the lack of fully biocompatible fabrication techniques, a novel visible light printer is proposed. Optimization processes are presented for each printing technology which are beneficial for the wider research community. Overall, for the first time, this thesis demonstrates the possibility to fabricate a phytocompatible hydrogel with complex 3D printable designs. A series of tests is conducted to create fully perfusable channels with a minimum channel width of 250 μm. The fabrication of an architecturally complex structure demonstrates an increased bioreceptivity with respect to a solid gel. Long term plant growth is proven on selected materials to evidence the future possibility of using 3D printed hydrogels for soilless cultivation.