The worldwide transition from the use of oil-based to more sustainable feedstocks for plastics is underway. This transition is due to dwindling oil stocks and a realisation that current levels of the use of this resource is no longer sustainable. More sustainable sources for materials use exist in the form of cellulose from plants. This material is a very versatile polymer and is in fact the most utilised material worldwide. For the last 20+ years I have been researching the structure-property relationships of cellulose and am ideally placed to play a key role in the transition to renewable materials. Nature makes use of cellulose to good effect. Being intrinsically strong and stiff means that cellulose fibres, per weight, can compete mechanically with most synthetic alternatives such as glass. In nature's most prevalent natural composite - wood - cellulose forms the basis of its outstanding structural performance. All our attempts to replicate the composite performance of wood and plants have fallen short, and this fellowship seeks to address these issues, while also using the intrinsic properties of plant fibres and wood themselves. The proposed research aims to do this in the context of both natural and synthetic materials, adding functionality to the composites, while also addressing in a cross-cutting sense the sustainability credentials of the materials and structures proposed.