Self-assembly meets additive manufacturing: Bridging the gap between nanoscale arrangement of matter and macroscale fabrication

New methods are emerging to combine the self-assembly of matter and additive manufacturing, so that new devices and constructs can simultaneously harness the unique molecular and nanostructural features afforded by self-assembly and the macroscale design freedom of additive manufacturing. The aim of this review is to analyse the body of literature and explore the crossover area where boundaries dissolve and self-assembly meets additive manufacturing (SAMAM). As a preliminary framework for this new area of research, the different experimental approaches to SAMAM can be grouped in three main categories, whereby SAMAM can be based on local interactions between molecules or nanoparticles, on 3D-printing induced forces, or on externally applied force fields. SAMAM offers numerous opportunities, such as the design of new printable materials, the ability to surpass conventional trade-offs in materials properties, the control of structural features across different length scales, process intensification and improved eco-sustainability. However, most research so far has been focused on polymer-based materials, and additional effort is needed to understand how SAMAM can be leveraged in metal- and ceramic-based additive manufacturing. On account of the weak inter-layer bonding often reported along the growth direction, it would also be interesting to explore whether SAMAM could effectively remediate undesidered anisotropic effects in additively manufactured parts.