4D fibrous materials: characterising the deployment of paper architectures

Deployment of folded paper architecture using a fluid medium as the morphing stimulus presents a simple and inexpensive methodology capable of self-actuation; where the underlying principles can be translated to develop smart fibrous materials capable of programmable actuations. In this study we characterise different paper architectures and their stimuli mechanisms for folded deployment; including the influence of porosity, moisture, surfactant concentration, temperature, and hornification. We observe that actuation time decreases with paper grammage; through the addition of surfactants, and when the temperature is increased at the fluid-vapour interface. There is a clear effect of hydration, water transport and the interaction of hydrogen bonds within the fibrous architecture which drives the deployment of the folded regions. The importance of fibre volume fraction and functional fillers in shape recovery was also observed, as well as the effect of a multilayer composite paper system. The design guidelines shown here will inform the development of synthetic fibrous actuators for repeated deployment.</p

Australia's Great Barrier Reef

Australia’s Great Barrier Reef (the GBR) is an iconic natural ecosystem, globally renowned for its majesty and grandeur. The GBR encompasses a vast array of unique and important marine and terrestrial habitats, from deepwater reefs to archetypal barrier reefs, as well as vast seagrass and algal meadows, intertidal mud flats, sand cays, and continental islands. The variety of environments and habitats encompassed within the GBR gives rise to extraordinary biodiversity. The GBR is also unusual compared with most reef systems around the world because the islands and adjacent coastal areas are sparsely populated. Moreover, Australia is a developed economy and does not generally rely heavily on subsistence or artisanal extraction of reef resources. That said, the GBR is being increasingly threatened by anthropogenic activities, such as land clearing and agricultural runoff, coastal development, pollution, and above all, increasing global carbon emissions that are rapidly changing environmental conditions. Sustained and ongoing global climate change has culminated in unprecedented and recurrent mass coral bleaching in recent years, which now represents the foremost threat to the integrity, functioning, and biodiversity of coral reef environments. Significant investment and effort is committed to conserving the GBR, both to maintain the ecological function and human benefits derived from the various natural systems, but the effectiveness and longer-term benefit of established and renewed management actions are conditional on immediate and effective action to reduce global carbon emissions