The evolution of ABC star polymers: from trial-and-error to rational design.

ABC star polymers, consisting of three chemically distinct polymeric chains bound to a common point, have emerged over the last 35 years as versatile materials with tunable morphologies and potential applications in nanofabrication, drug delivery, or solid-state electrolytes. Despite decades of progress, well-defined synthesis and design remain a challenge due to their high synthetic complexity. This review surveys key developments in synthetic strategies, ranging from early anionic routes to modern reversible-deactivation radical polymerizations and click-driven methods, highlighting the trade-offs between architectural precision, functional compatibility, and scalability. Particular emphasis is placed on the resulting morphologies in bulk, thin-film, and solution states, where the star topology enables unique structural motifs not accessible to linear triblocks. These include complex tilings, hierarchical phases, and multicompartment micelles. Emerging computational and data-driven approaches are discussed in the context of inverse design, offering new directions for bridging idealized model systems with scalable, application-ready materials.