  Mechanical metamaterials, whose unique mechanical properties stem from their
structural design rather than material constituents, are gaining popularity in
engineering applications. In particular, recent advances in self-assembly
techniques offer the potential to fabricate load-bearing mechanical
metamaterials with unparalleled feature size control and scalability compared
to those produced by additive manufacturing (AM). Yet, the field is still in
its early stages. In this perspective, we first provide an overview of the
state-of-the-art self-assembly techniques, with a focus on the copolymer and
colloid crystal self-assembly processes. We then discuss current challenges and
future opportunities in this research area, focusing on novel fabrication
approaches, the need for high-throughput characterization methods, and the
integration of Machine Learning (ML) and lab automation for inverse design.
Given recent progress in all these areas, we foresee mechanical metamaterials
fabricated from self-assembly techniques impacting a variety of applications
relying on lightweight, strong, and tough materials.
