Toward Sustainable 3D Printing

Abstract

Additive manufacturing (AM) technologies are disrupting our society by proposing a faster and customizable way of producing parts. Along with the technological advances, the environmental, economic, and societal aspects of AM must also be addressed to create a sustainable future. In this viewpoint, I will briefly introduce three key challenges towards this goal, that are the materials diversity, the mechanical strength and stiffness and the use of green affordable materials. After describing our recent efforts, I will discuss forthcoming difficulties and alternatives, and stress the need for aligned research across communities.

Controlled local orientation of 2D nanomaterials in 3D devices: methods and prospects for multifunctional designs and enhanced performance

“…First described in the 1980s by Charles Hull regarding the stereolithography (SLA) process, 3D printing technology has evolved into multiple printing forms such as inkjet printing, direct ink writing, powder bed fusion, selective laser sintering and so on. 261–268 Overall, 3D printing techniques can mainly be classified into three types based on the material feedstock: slurry-based, powder-based and bulk solid-based. Each printing method possesses its own technical features in terms of the equipment setup, feedstock material requirement, and printing advantages and limitations.…”

“…The recent progress in 3D printing has been summarized in a few comprehensive reviews. 262–264,268–271 A few studies report the use of fused deposition modelling (FDM) using graphene but the fabrication of thermoplastic filaments with homogeneously distributed 2D nanosheets is challenging. 272,273 In FDM, a thermoplastic filament is heated and extruded through a nozzle on a substrate, where it cools down to solidify.…”

“…20c, the as-prepared ink is extruded from a printing nozzle as a continuous filament, and deposited in a layer-by-layer manner following a predefined pattern, just as directly “writing”. 268,283,284 Then, the printed filaments are consolidated by curing under heat or light, other chemical reactions, dried or frozen, depending on the matrix composition used in the ink. As the quality of final printed parts is entirely determined by the rheological properties of the ink, a wide range of 2D nanomaterials can be obtained.…”

Closed-Loop Additive Manufacturing: Dynamic Covalent Networks in Vat Photopolymerization

“…AM promises a reduced amount of plastic waste generated in the process with respect to conventional subtractive manufacturing . However, the quantitative environmental impact is still in debate, since life cycle assessments (LCAs) that compare AM with established fabrication techniques are challenging to conduct . While FDM and SLS rely on reprocessable thermoplastic inks, vat photopolymerization typically creates thermosets with permanently cross-linked polymeric networks .…”

Introducing Viewpoints

“…In this issue, we are proud to include a new PI Viewpoint from Hortense Le Ferrand, who is a National Research Foundation (NRF) Fellow and an Assistant Professor in the Schools of Mechanical and Aerospace Engineering and Materials Science and Engineering at Nanyang Technological University, Singapore. She discusses a few key challenges and possible alternatives for achieving "sustainable 3D printing", 6 such as making additive manufacturing more materials agnostic yet achieving desirable mechanical integrity of printed structures. She also advocates for the development of green and affordable ink materials to make 3D printing technologies more inclusive and accessible.…”