Abstract
With our past set in stone, bronze, and iron, and our present cast in plastic, human history has always been defined by our materials. Though our future has yet to be written, what was once shrouded in a cloud of uncertainty is now slowly unraveling; the course of human development, if navigated unchanged, will surely run us ashore. And if materials shape human development, new materials, and new ways of using them can allow us to picture a different ending — one that makes our struggle to conserve life on Earth a distant memory, and the tools and paradigms created to avoid such a fated finale the keys to reaching some of humanity’s most remarkable feats. This thesis takes a stab at the multifaceted challenge of sustainable development, and in particular, sustainable manufacturing. It aims to explain and adapt the tools and principles of biological manufacturing and its materials to produce artificial construction. Such tools enable the development of manufacturing models in which sustainability does not arise from the adaptation of existing production methods to our ongoing understanding of environmental impact. Instead, it arises from a manufacturing paradigm based on endogenous processes and materials as part of ecological cycles. The undertone of this thesis moves beyond reporting a curated collection of scientific data and portrays a future driven by science and the collective will it envisions. Chapter 1 begins with an introduction and a brief history of materials development. It explores the context of how humanity, after centuries of materials development focused on mechanical and electrical properties, inadvertently rose to a dominant position of ecological influence, capable of effecting long-term changes across all of nature. It then provides an explanation of how our increasing awareness and understanding of the magnitude and consequences of this ecological impact are transforming the sustainability of materials into one of the primary drivers in the field. Then, it builds on the case of natural materials, which develop in a paradigm of low energy demand and closed-loop resource utilization and are inherently linked to efficient and ecologically integrated economies and society models. Specifically, it highlights the advantages of a ubiquitous structural biopolymer —chitin— and discusses its associated opportunities and existing applications. The chapter concludes with a brief discussion of chitinous composites, highlighting their potential role in enabling the general adoption of natural materials in engineering. v The environmental sustainability of chitinous composites is assessed in Chapter 2, providing scientific formality to the analysis of the material environmental impact, and setting the groundwork for the discussion on sustainability that comprises the backbone of this thesis. The lifecycle of material production is thoroughly analysed in several scenarios, highlighting the advantages, room for improvements, and technological steps necessary to maximize the environmental potential of chitinous composites in manufacturing. The chapter concludes with a brief outline of process optimization opportunities, beyond the current industrial paradigm, for new applications of chitinous manufacturing. One such new application of chitinous manufacturing is introduced in Chapter 3—an entirely new approach to metalworking, based on the processes occurring in arthropodan cuticles during molting. The new methodology capitalises on the affinity between chitin and metals, allowing traditional metalworking processes requiring high energy and temperatures, such as casting, printing, and coating, to occur at the low-energy biological conditions of standard pressure and temperature and using water as the only solvent. The chapter ends by demonstrating that the affinity of the processes with biological components enables extending the methodology to other bio-based manufacturing and materials within the same paradigm. This is proven by imbuing large cellulosic constructs with metallic characteristics. Given that chitin is a ubiquitous resource in every ecological cycle on Earth, a focus of this thesis is the adaptation and integration of chitinous manufacturing in the surrounding ecosystem. In Chapter 4, we move beyond this goal to the parallel development of an artificial ecosystem in a lifeless environment scenario. This is the scenario of an imminent future for humanity beyond Earth, and is characterised by endeavors requiring entirely self-sufficient, persistent human presence in the absence of naturally occurring biological resources. This chapter tackles the development of chitinous manufacturing and its associated artificial ecosystem to establish a human settlement on Mars. The solution borrows from biological manufacturing, the efficient use of resources, and the minimization of processes by enhancing the versatility of the materials. The chapter concludes by describing the potential uses of chitin in resource-scarce environments beyond Mars for the parallel development of general manufacturing and a closed-loop artificial ecosystem—whether for nations facing supply chain disruption, scientists at Earth’s distant polar regions, or astronauts at the international space station. vi This thesis begins by examining material development from prehistoric times, continues with the optimization of current manufacturing, and ends by setting up part of the foundation for a future of interplanetary humanity. Chapter 5 ties together these scientific works as realised technological steps within a broad, biology-based manufacturing transformation. This chapter aims to summarise the previous discussion and share with the reader the vision and characteristics of a drastically different manufacturing paradigm.