Preview

PDF, English Download (7MB) | Terms of use

Abstract

Over recent decades 3D printing, or additive manufacturing, has become an invaluable fabrication method, making a significant impact across many sectors of society. With the development of new printing techniques and printable materials, great progress has been made, particularly on the macroscale. However, as a result of key technological advances, 3D printing on the micro and nanoscale has also become more accessible. To that end, two-photon laser printing (2PLP) has emerged as one of the most suitable and useful methods for fabricating complex objects with arbitrary geometries and fine features. As these technologies progress, the need for more advanced and functional materials becomes evident. With further developments in synthetic methods, new and advanced macromolecular architectures once unattainable have become more readily available. The current library of materials typically used as inks for 2PLP fall into the category of multifunctional small molecules or functionalised polymers containing a distribution of crosslinkable groups. Despite developments toward functional inks with novel properties for 2PLP, the underlying relationships between the properties of the macromolecules used as inks and their behaviour during printing, as well as the effects on the resultant printed structures, remain underexplored. To that end, the work herein examines the rational design of macromolecular inks for 2PLP with precise control and previously unexplored architectures, to investigate the effects of the (macro)molecular architecture on the printability and subsequently, in the printed microstructures. Three overarching concepts are explored in this regard: firstly, the design of pre-polymer inks with tailored comonomer composition, with varied physicochemical properties such as glass transition temperature and molecular weight. Secondly, an approach to determine the effect of molecular sequence, whereby sequence-defined oligomers are printed for the first time. With identical composition, varying only in the sequence of crosslinkable groups, clear differences in properties are observed. Lastly, leveraging the potential afforded by synthetic advances in polymer architecture design, novel macromolecular bottlebrushes are developed as inks for 2PLP. The common thread throughout these chapters, is the investigation of relationships between synthetic design, 3D printing, and material properties, highlighting the benefits of rationally designing macromolecular inks toward the goal of fabricating objects with specific and tailorable properties. Understanding and exploring these relationships becomes particularly relevant in the rapidly expanding field of functional material development for future 2PLP applications.